Develop Reference

Android - Child view touch positions incorrect

I have a RelativeLayout which has a ViewDragHelper which I use to move the view around. I have to use layout(boolean changed, int left, int top, int right, int bottom) to update view size on drag because the views inside need to resize. This all works fine. Now the child views inside have their touch positions all wrong. Buttons work as if they were on top of the screen as opposed to where they are.
private void changeDragViewPosition(int top, float verticalMovementFactor) {
int right = calculateViewRightPosition(verticalMovementFactor);
int left = right - mainViewLayoutParams.width;
int bottom = top + mainViewLayoutParams.height;
mainView.layout(left, top, right, bottom);
}
This is the code I use for moving the view. The mainView itself has correct touch positions, the child views inside this view are the problem. Is there anything I'm missing?
EDIT
Here is the view i'm using.
public class MinimizableView extends RelativeLayout {
private static final int DEFAULT_MINIMIZED_MARGIN = 2;
private static final int DEFAULT_SCALE_FACTOR = 2;
private static final int MIN_SLIDING_DISTANCE_ON_CLICK = 10;
private View mainView;
private View unmovableView;
private ArrayList<View> otherViews;
private ArrayList<Integer> initialPositions;
private LayoutParams mainViewLayoutParams;
private int verticalDragRange;
private int mainViewOriginalWidth;
private int mainViewOriginalHeight;
private float scaleFactor = DEFAULT_SCALE_FACTOR;
private float minimizedMargin;
private boolean firstLayoutPass = true;
private int mainViewInitialPosition;
private float lastTouchActionDownXPosition;
private ViewDragHelper viewDragHelper;
private MinimizableViewListener listener;
public interface MinimizableViewListener {
void onMinimized();
void onMaximized();
void onClosed();
}
public MinimizableView(Context context) {
super(context);
init(context);
}
public MinimizableView(Context context, AttributeSet attrs) {
super(context, attrs);
init(context);
}
public MinimizableView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init(context);
}
private void init(Context context) {
minimizedMargin = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, DEFAULT_MINIMIZED_MARGIN, getResources().getDisplayMetrics());
ViewCompat.requestApplyInsets(this);
}
private ViewDragHelper.Callback viewDragHelperCallback = new ViewDragHelper.Callback() {
private static final int MINIMUM_DX_FOR_HORIZONTAL_DRAG = 5;
private static final int MINIMUM_DY_FOR_VERTICAL_DRAG = 15;
private static final float X_MIN_VELOCITY = 1500;
private static final float Y_MIN_VELOCITY = 1000;
#Override
public boolean tryCaptureView(View child, int pointerId) {
return child.equals(mainView);
}
#Override
public void onViewPositionChanged(View changedView, int left, int top, int dx, int dy) {
if (!isMainViewAtBottom()) {
float verticalMovementFactor = (top - mainViewInitialPosition) / (float) verticalDragRange;
changeDragViewScale(verticalMovementFactor);
changeDragViewPosition(top, verticalMovementFactor);
changeSecondViewAlpha(verticalMovementFactor);
changeSecondViewPosition(verticalMovementFactor);
changeUnmovableViewAlpha(verticalMovementFactor);
}
}
#Override
public void onViewReleased(View releasedChild, float xvel, float yvel) {
super.onViewReleased(releasedChild, xvel, yvel);
if (isMainViewAtBottom() && !isViewAtRight(releasedChild)) {
triggerOnReleaseActionsWhileHorizontalDrag(xvel);
} else {
triggerOnReleaseActionsWhileVerticalDrag(yvel);
}
}
#Override
public int clampViewPositionVertical(View child, int top, int dy) {
int newTop = verticalDragRange + mainViewInitialPosition;
if (isMinimized() && Math.abs(dy) >= MINIMUM_DY_FOR_VERTICAL_DRAG || (!isMinimized() && !isMainViewAtBottom())) {
final int topBound = getPaddingTop() + mainViewInitialPosition;
final int bottomBound = verticalDragRange + mainViewInitialPosition;
newTop = Math.min(Math.max(top, topBound), bottomBound);
}
return newTop;
}
#Override
public int clampViewPositionHorizontal(View child, int left, int dx) {
int newLeft = mainView.getLeft();
if ((isMinimized() && Math.abs(dx) > MINIMUM_DX_FOR_HORIZONTAL_DRAG) || (isMainViewAtBottom() && !isViewAtRight(mainView))) {
newLeft = left;
}
return newLeft;
}
private void triggerOnReleaseActionsWhileHorizontalDrag(float xvel) {
if (xvel < 0 && xvel <= -X_MIN_VELOCITY) {
closeToLeft();
} else if (xvel > 0 && xvel >= X_MIN_VELOCITY) {
closeToRight();
} else {
if (isNextToLeftBound(mainView)) {
closeToLeft();
} else if (isNextToRightBound(mainView)) {
closeToRight();
} else {
minimize();
}
}
}
private void triggerOnReleaseActionsWhileVerticalDrag(float xvel) {
if (xvel < 0 && xvel <= -Y_MIN_VELOCITY) {
maximize();
} else if (xvel > 0 && xvel >= Y_MIN_VELOCITY) {
minimize();
} else {
if (isDragViewAboveTheMiddle(mainView)) {
maximize();
} else {
minimize();
}
}
}
};
private void changeDragViewScale(float verticalMovementFactor) {
mainViewLayoutParams.width = (int) (mainViewOriginalWidth * (1 - (verticalMovementFactor / scaleFactor)));
mainViewLayoutParams.height = (int) (mainViewOriginalHeight * (1 - (verticalMovementFactor / scaleFactor)));
mainView.setLayoutParams(mainViewLayoutParams);
}
private void changeDragViewPosition(int top, float verticalMovementFactor) {
int right = calculateViewRightPosition(verticalMovementFactor);
int left = right - mainViewLayoutParams.width;
int bottom = top + mainViewLayoutParams.height;
mainView.layout(left, top, right, bottom);
}
private void changeSecondViewAlpha(float verticalMovementFactor) {
for (int i = 0; i < otherViews.size(); i++) {
otherViews.get(i).setAlpha(1 - verticalMovementFactor);
}
}
private void changeSecondViewPosition(float verticalMovementFactor) {
int newTop;
int initialTop;
for (int i = 0; i < otherViews.size(); i++) {
initialTop = initialPositions.get(i);
newTop = (int) (initialTop + ((getBottom() - initialTop) * verticalMovementFactor));
otherViews.get(i).setY(newTop);
}
}
private void changeUnmovableViewAlpha(float verticalMovementFactor) {
unmovableView.setAlpha(1 - verticalMovementFactor);
}
private int calculateViewRightPosition(float verticalMoveFactor) {
return (int) (mainViewOriginalWidth - minimizedMargin * verticalMoveFactor);
}
private boolean isDragViewAboveTheMiddle(View view) {
int parentHeight = getHeight();
float viewYPosition = view.getY() + (view.getHeight() * 0.5f);
return viewYPosition < (parentHeight * 0.5);
}
private boolean isMainViewAtTop() {
return mainView.getTop() == mainViewInitialPosition;
}
private boolean isMainViewAtBottom() {
return mainView.getBottom() >= getBottom() - getPaddingBottom() - minimizedMargin - 1;
}
private boolean isViewAtRight(View view) {
return view.getRight() + minimizedMargin + 10 >= getWidth() - 10;
}
private void closeToLeft() {
if (viewDragHelper.smoothSlideViewTo(mainView, -mainViewOriginalWidth, getHeight() - getMinHeightPlusMargin())) {
ViewCompat.postInvalidateOnAnimation(this);
}
if (listener != null) {
listener.onClosed();
}
}
private int getMinHeightPlusMargin() {
return (int) (mainViewOriginalHeight * (1 - 1 / scaleFactor) + minimizedMargin);
}
private int getMinWidthPlusMargin() {
return (int) (mainViewOriginalWidth * (1 - 1 / scaleFactor) + minimizedMargin);
}
private void closeToRight() {
if (viewDragHelper.smoothSlideViewTo(mainView, mainViewOriginalWidth, getHeight() - getMinHeightPlusMargin())) {
ViewCompat.postInvalidateOnAnimation(this);
}
if (listener != null) {
listener.onClosed();
}
}
private boolean isNextToLeftBound(View view) {
return (view.getLeft() - minimizedMargin) < getWidth() * 0.05;
}
private boolean isNextToRightBound(View view) {
return (view.getLeft() - minimizedMargin) > getWidth() * 0.75;
}
private boolean isViewHit(View view, int x, int y) {
int[] viewLocation = new int[2];
view.getLocationOnScreen(viewLocation);
int[] parentLocation = new int[2];
this.getLocationOnScreen(parentLocation);
int screenX = parentLocation[0] + x;
int screenY = parentLocation[1] + y;
return screenX >= viewLocation[0]
&& screenX < viewLocation[0] + view.getWidth()
&& screenY >= viewLocation[1]
&& screenY < viewLocation[1] + view.getHeight();
}
private static final int INVALID_POINTER = -1;
private int activePointerId;
#Override
public boolean onTouchEvent(MotionEvent event) {
int actionMasked = MotionEventCompat.getActionMasked(event);
if ((actionMasked & MotionEventCompat.ACTION_MASK) == MotionEvent.ACTION_DOWN) {
activePointerId = MotionEventCompat.getPointerId(event, actionMasked);
}
if (activePointerId == INVALID_POINTER) {
return false;
}
viewDragHelper.processTouchEvent(event);
if (isClosed()) {
return false;
}
boolean isDragViewHit = isViewHit(mainView, (int) event.getX(), (int) event.getY());
boolean isSecondViewHit = false;
for (int i = 0; i < otherViews.size(); i++) {
if (isViewHit(otherViews.get(i), (int) event.getX(), (int) event.getY())) {
isSecondViewHit = true;
break;
}
}
analyzeTouchToMaximizeIfNeeded(event, isDragViewHit);
if (isMaximized()) {
mainView.dispatchTouchEvent(event);
} else {
mainView.dispatchTouchEvent(cloneMotionEventWithAction(event, MotionEvent.ACTION_CANCEL));
}
return isDragViewHit || isSecondViewHit;
}
private void analyzeTouchToMaximizeIfNeeded(MotionEvent ev, boolean isDragViewHit) {
switch (ev.getAction()) {
case MotionEvent.ACTION_DOWN:
lastTouchActionDownXPosition = ev.getX();
break;
case MotionEvent.ACTION_UP:
float clickOffset = ev.getX() - lastTouchActionDownXPosition;
if (shouldMaximizeOnClick(ev, clickOffset, isDragViewHit)) {
if (isMinimized()) {
maximize();
}
}
break;
default:
break;
}
}
public boolean shouldMaximizeOnClick(MotionEvent ev, float deltaX, boolean isDragViewHit) {
return (Math.abs(deltaX) < MIN_SLIDING_DISTANCE_ON_CLICK) && ev.getAction() != MotionEvent.ACTION_MOVE && isDragViewHit;
}
private MotionEvent cloneMotionEventWithAction(MotionEvent event, int action) {
return MotionEvent.obtain(event.getDownTime(), event.getEventTime(), action, event.getX(), event.getY(), event.getMetaState());
}
#Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
if (!isEnabled()) {
return false;
}
switch (MotionEventCompat.getActionMasked(ev) & MotionEventCompat.ACTION_MASK) {
case MotionEvent.ACTION_CANCEL:
case MotionEvent.ACTION_UP:
viewDragHelper.cancel();
return false;
case MotionEvent.ACTION_DOWN:
int index = MotionEventCompat.getActionIndex(ev);
activePointerId = MotionEventCompat.getPointerId(ev, index);
if (activePointerId == INVALID_POINTER) {
return false;
}
break;
default:
break;
}
boolean interceptTap = viewDragHelper.isViewUnder(mainView, (int) ev.getX(), (int) ev.getY());
return viewDragHelper.shouldInterceptTouchEvent(ev) || interceptTap;
}
#Override
protected void onFinishInflate() {
super.onFinishInflate();
otherViews = new ArrayList<>();
initialPositions = new ArrayList<>();
int childCount = getChildCount();
for (int i = 0; i < childCount; i++) {
View child = getChildAt(i);
if (child instanceof DragView) {
mainView = child;
} else if (child instanceof UnmovableView) {
unmovableView = child;
} else {
otherViews.add(child);
}
}
viewDragHelper = ViewDragHelper.create(this, 1, viewDragHelperCallback);
mainViewLayoutParams = (LayoutParams) mainView.getLayoutParams();
}
#Override
public void computeScroll() {
if (!isInEditMode() && viewDragHelper.continueSettling(true)) {
ViewCompat.postInvalidateOnAnimation(this);
}
}
#Override
protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
if (isInEditMode() || firstLayoutPass) {
super.onLayout(changed, left, top, right, bottom);
mainViewInitialPosition = mainView.getTop();
verticalDragRange = getMeasuredHeight() - mainViewInitialPosition - getMinHeightPlusMargin() - getPaddingTop() - getPaddingBottom();
for (int i = 0; i < otherViews.size(); i++) {
initialPositions.add(otherViews.get(i).getTop());
}
firstLayoutPass = false;
} else if (isMainViewAtTop()) {
mainView.layout(left, mainViewInitialPosition, right, mainViewInitialPosition + mainViewOriginalHeight);
changeUnmovableViewAlpha(0);
setLayoutPositions(0, left, right, bottom, true);
} else {
setLayoutPositions(mainView.getTop() / (float) verticalDragRange, left, right, bottom, false);
}
}
private void setLayoutPositions(float offsetFactor, int left, int right, int bottom, boolean setY) {
int newTop;
int initialTop;
for (int i = 0; i < otherViews.size(); i++) {
View view = otherViews.get(i);
initialTop = initialPositions.get(i);
newTop = (int) (initialTop + ((bottom - initialTop) * offsetFactor));
view.layout(left, newTop, right, newTop + view.getHeight());
if (setY) {
view.setY(newTop);
}
}
}
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
if (mainViewOriginalWidth == 0) {
mainViewOriginalWidth = mainView.getMeasuredWidth();
mainViewOriginalHeight = mainView.getMeasuredHeight();
}
}
private boolean smoothSlideTo(float slideOffset) {
final int topBound = mainViewInitialPosition + getPaddingTop();
int x = (int) (slideOffset * (getWidth() - getMinWidthPlusMargin()));
int y = (int) ((slideOffset * verticalDragRange) + topBound);
if (viewDragHelper.smoothSlideViewTo(mainView, x, y)) {
ViewCompat.postInvalidateOnAnimation(this);
return true;
}
return false;
}
#Override
public void setPadding(int left, int top, int right, int bottom) {
super.setPadding(left, top, right, bottom);
mainViewInitialPosition = mainView.getTop();
verticalDragRange = getMeasuredHeight() - mainViewInitialPosition - getMinHeightPlusMargin() - getPaddingTop() - getPaddingBottom();
for (int i = 0; i < otherViews.size(); i++) {
initialPositions.add(otherViews.get(i).getTop());
}
}
// --------- PUBLIC METHODS ---------- //
public void maximize() {
smoothSlideTo(0);
if (listener != null) {
listener.onMaximized();
}
}
public void minimize() {
smoothSlideTo(1);
if (listener != null) {
listener.onMinimized();
}
}
public boolean isMinimized() {
return isMainViewAtBottom() && isViewAtRight(mainView);
}
public boolean isMaximized() {
return mainView.getTop() == mainViewInitialPosition;
}
public boolean isClosed() {
return mainView.getRight() <= 0 && mainView.getLeft() >= getWidth();
}
public void setMinimizableViewListener(MinimizableViewListener listener) {
this.listener = listener;
}
public void hide() {
changeDragViewScale(1);
changeDragViewPosition(verticalDragRange + mainViewInitialPosition - getMinHeightPlusMargin(), 1);
minimize();
setVisibility(GONE);
}
public void show() {
setVisibility(VISIBLE);
post(new Runnable() {
#Override
public void run() {
maximize();
}
});
}
}
As you can see the I have overridden the onTouch method and it works fine. I also have a button inside the mainView which is also a RelativeLayout.
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.lycatv.dragviewtest.MainActivity">
<android.support.v7.widget.Toolbar
android:id="#+id/actionBar1"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#+id/actionBar1"
android:fitsSystemWindows="true"
android:text="Hello World!" />
<com.lycatv.dragviewtest.MinimizableView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="56dp">
<com.lycatv.dragviewtest.UnmovableView
android:id="#+id/actionBar"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<android.support.v7.widget.Toolbar
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimaryDark" />
</com.lycatv.dragviewtest.UnmovableView>
<FrameLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_below="#+id/actionBar"
android:background="#1a1e39" />
<FrameLayout
android:id="#+id/frameLayout1"
android:layout_width="match_parent"
android:layout_height="48dp"
android:layout_below="#+id/actionBar" />
<com.lycatv.dragviewtest.DragView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="#+id/frameLayout1">
<ImageView
android:layout_width="match_parent"
android:layout_height="200dp"
android:src="#000000" />
<CheckBox
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="bottom"
android:text="CheckBox"
android:textColor="#android:color/white" />
</com.lycatv.dragviewtest.DragView>
</com.lycatv.dragviewtest.MinimizableView>
The CheckBox does not work when you press on it. Instead it works when you press above it. By whatever amount it is offset from the top.

I won't pretend to understand everything your code is doing. However, I did notice something in onLayout that is almost certainly wrong. The code you posted is this:
#Override
protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
if (isInEditMode() || firstLayoutPass) {
super.onLayout(changed, left, top, right, bottom);
mainViewInitialPosition = mainView.getTop();
verticalDragRange = getMeasuredHeight() - mainViewInitialPosition - getMinHeightPlusMargin() - getPaddingTop() - getPaddingBottom();
for (int i = 0; i < otherViews.size(); i++) {
initialPositions.add(otherViews.get(i).getTop());
}
firstLayoutPass = false;
} else if (isMainViewAtTop()) {
mainView.layout(left, mainViewInitialPosition, right, mainViewInitialPosition + mainViewOriginalHeight);
changeUnmovableViewAlpha(0);
setLayoutPositions(0, left, right, bottom, true);
} else {
setLayoutPositions(mainView.getTop() / (float) verticalDragRange, left, right, bottom, false);
}
}
The almost-certain error in this code is in your use of the layout method here:
mainView.layout(left, mainViewInitialPosition, right, mainViewInitialPosition + mainViewOriginalHeight);
You are using the parameter values left and right to layout your mainView (and the child views via setLayoutPositions). This is wrong. Keep in mind that left, top, right and bottom are the relative positions of your parent view (MinimizableView); they should not be used directly to layout your child views, as the child views are relative to MinimizableView, not to the parent of MinimizableView.
For example, when you layout mainView, the values you pass into layout() are interpreted as being relative to MinimizableView. This means the left offset should be 0 (plus padding), not left. Diddo for right. You layout call should look more like:
mainView.layout(0, 0, mainView.getMeasuredWidth(), mainView.getMeasuredHeight());
Note that the above does not account for padding.

Swipe refresh layout is not working for web view.

I am using swipe refresh layout but it is not working for web view. It is working for a simple activity layout, but when i am using a web view it's not working properly.
Here is my code.
public class SwipeActivity extends Activity implements OnRefreshListener{
SwipeRefreshLayout swipeLayout;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_swipe);
swipeLayout = (SwipeRefreshLayout) findViewById(R.id.swipe_container);
swipeLayout.setOnRefreshListener(this);
swipeLayout.setColorScheme(android.R.color.holo_blue_bright,
android.R.color.holo_green_light,
android.R.color.holo_orange_light,
android.R.color.holo_red_light);
}
public void onRefresh() {
new Handler().postDelayed(new Runnable() {
#Override public void run() {
swipeLayout.setRefreshing(false);
}
}, 5000);
}
}
And this one is swipe refresh layout.
public class SwipeRefreshLayout extends ViewGroup {
private static final long RETURN_TO_ORIGINAL_POSITION_TIMEOUT = 300;
private static final float ACCELERATE_INTERPOLATION_FACTOR = 1.5f;
private static final float DECELERATE_INTERPOLATION_FACTOR = 2f;
private static final float PROGRESS_BAR_HEIGHT = 4;
private static final float MAX_SWIPE_DISTANCE_FACTOR = .6f;
private static final int REFRESH_TRIGGER_DISTANCE = 120;
private SwipeProgressBar mProgressBar; //the thing that shows progress is going
private View mTarget; //the content that gets pulled down
private int mOriginalOffsetTop;
private OnRefreshListener mListener;
private MotionEvent mDownEvent;
private int mFrom;
private boolean mRefreshing = false;
private int mTouchSlop;
private float mDistanceToTriggerSync = -1;
private float mPrevY;
private int mMediumAnimationDuration;
private float mFromPercentage = 0;
private float mCurrPercentage = 0;
private int mProgressBarHeight;
private int mCurrentTargetOffsetTop;
// Target is returning to its start offset because it was cancelled or a
// refresh was triggered.
private boolean mReturningToStart;
private final DecelerateInterpolator mDecelerateInterpolator;
private final AccelerateInterpolator mAccelerateInterpolator;
private static final int[] LAYOUT_ATTRS = new int[] {
android.R.attr.enabled
};
private final Animation mAnimateToStartPosition = new Animation() {
#Override
public void applyTransformation(float interpolatedTime, Transformation t) {
int targetTop = 0;
if (mFrom != mOriginalOffsetTop) {
targetTop = (mFrom + (int)((mOriginalOffsetTop - mFrom) * interpolatedTime));
}
int offset = targetTop - mTarget.getTop();
final int currentTop = mTarget.getTop();
if (offset + currentTop < 0) {
offset = 0 - currentTop;
}
setTargetOffsetTopAndBottom(offset);
}
};
private Animation mShrinkTrigger = new Animation() {
#Override
public void applyTransformation(float interpolatedTime, Transformation t) {
float percent = mFromPercentage + ((0 - mFromPercentage) * interpolatedTime);
mProgressBar.setTriggerPercentage(percent);
}
};
private final AnimationListener mReturnToStartPositionListener = new BaseAnimationListener() {
#Override
public void onAnimationEnd(Animation animation) {
// Once the target content has returned to its start position, reset
// the target offset to 0
mCurrentTargetOffsetTop = 0;
}
};
private final AnimationListener mShrinkAnimationListener = new BaseAnimationListener() {
#Override
public void onAnimationEnd(Animation animation) {
mCurrPercentage = 0;
}
};
private final Runnable mReturnToStartPosition = new Runnable() {
#Override
public void run() {
mReturningToStart = true;
animateOffsetToStartPosition(mCurrentTargetOffsetTop + getPaddingTop(),
mReturnToStartPositionListener);
}
};
// Cancel the refresh gesture and animate everything back to its original state.
private final Runnable mCancel = new Runnable() {
#Override
public void run() {
mReturningToStart = true;
// Timeout fired since the user last moved their finger; animate the
// trigger to 0 and put the target back at its original position
if (mProgressBar != null) {
mFromPercentage = mCurrPercentage;
mShrinkTrigger.setDuration(mMediumAnimationDuration);
mShrinkTrigger.setAnimationListener(mShrinkAnimationListener);
mShrinkTrigger.reset();
mShrinkTrigger.setInterpolator(mDecelerateInterpolator);
startAnimation(mShrinkTrigger);
}
animateOffsetToStartPosition(mCurrentTargetOffsetTop + getPaddingTop(),
mReturnToStartPositionListener);
}
};
/**
* Simple constructor to use when creating a SwipeRefreshLayout from code.
* #param context
*/
public SwipeRefreshLayout(Context context) {
this(context, null);
}
/**
* Constructor that is called when inflating SwipeRefreshLayout from XML.
* #param context
* #param attrs
*/
public SwipeRefreshLayout(Context context, AttributeSet attrs) {
super(context, attrs);
mTouchSlop = ViewConfiguration.get(context).getScaledTouchSlop();
mMediumAnimationDuration = getResources().getInteger(
android.R.integer.config_mediumAnimTime);
setWillNotDraw(false);
mProgressBar = new SwipeProgressBar(this);
final DisplayMetrics metrics = getResources().getDisplayMetrics();
mProgressBarHeight = (int) (metrics.density * PROGRESS_BAR_HEIGHT);
mDecelerateInterpolator = new DecelerateInterpolator(DECELERATE_INTERPOLATION_FACTOR);
mAccelerateInterpolator = new AccelerateInterpolator(ACCELERATE_INTERPOLATION_FACTOR);
final TypedArray a = context.obtainStyledAttributes(attrs, LAYOUT_ATTRS);
setEnabled(a.getBoolean(0, true));
a.recycle();
}
#Override
public void onAttachedToWindow() {
super.onAttachedToWindow();
removeCallbacks(mCancel);
removeCallbacks(mReturnToStartPosition);
}
#Override
public void onDetachedFromWindow() {
super.onDetachedFromWindow();
removeCallbacks(mReturnToStartPosition);
removeCallbacks(mCancel);
}
private void animateOffsetToStartPosition(int from, AnimationListener listener) {
mFrom = from;
mAnimateToStartPosition.reset();
mAnimateToStartPosition.setDuration(mMediumAnimationDuration);
mAnimateToStartPosition.setAnimationListener(listener);
mAnimateToStartPosition.setInterpolator(mDecelerateInterpolator);
mTarget.startAnimation(mAnimateToStartPosition);
}
/**
* Set the listener to be notified when a refresh is triggered via the swipe
* gesture.
*/
public void setOnRefreshListener(SwipeActivity swipeActivity) {
mListener = swipeActivity;
}
private void setTriggerPercentage(float percent) {
if (percent == 0f) {
// No-op. A null trigger means it's uninitialized, and setting it to zero-percent
// means we're trying to reset state, so there's nothing to reset in this case.
mCurrPercentage = 0;
return;
}
mCurrPercentage = percent;
mProgressBar.setTriggerPercentage(percent);
}
/**
* Notify the widget that refresh state has changed. Do not call this when
* refresh is triggered by a swipe gesture.
*
* #param refreshing Whether or not the view should show refresh progress.
*/
public void setRefreshing(boolean refreshing) {
if (mRefreshing != refreshing) {
ensureTarget();
mCurrPercentage = 0;
mRefreshing = refreshing;
if (mRefreshing) {
mProgressBar.start();
} else {
mProgressBar.stop();
}
}
}
/**
* Set the four colors used in the progress animation. The first color will
* also be the color of the bar that grows in response to a user swipe
* gesture.
*
* #param colorRes1 Color resource.
* #param colorRes2 Color resource.
* #param colorRes3 Color resource.
* #param colorRes4 Color resource.
*/
public void setColorScheme(int colorRes1, int colorRes2, int colorRes3, int colorRes4) {
ensureTarget();
final Resources res = getResources();
final int color1 = res.getColor(colorRes1);
final int color2 = res.getColor(colorRes2);
final int color3 = res.getColor(colorRes3);
final int color4 = res.getColor(colorRes4);
mProgressBar.setColorScheme(color1, color2, color3,color4);
}
/**
* #return Whether the SwipeRefreshWidget is actively showing refresh
* progress.
*/
public boolean isRefreshing() {
return mRefreshing;
}
private void ensureTarget() {
// Don't bother getting the parent height if the parent hasn't been laid out yet.
if (mTarget == null) {
if (getChildCount() > 1 && !isInEditMode()) {
throw new IllegalStateException(
"SwipeRefreshLayout can host only one direct child");
}
mTarget = getChildAt(0);
mOriginalOffsetTop = mTarget.getTop() + getPaddingTop();
}
if (mDistanceToTriggerSync == -1) {
if (getParent() != null && ((View)getParent()).getHeight() > 0) {
final DisplayMetrics metrics = getResources().getDisplayMetrics();
mDistanceToTriggerSync = (int) Math.min(
((View) getParent()) .getHeight() * MAX_SWIPE_DISTANCE_FACTOR,
REFRESH_TRIGGER_DISTANCE * metrics.density);
}
}
}
#Override
public void draw(Canvas canvas) {
super.draw(canvas);
mProgressBar.draw(canvas);
}
#Override
protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
final int width = getMeasuredWidth();
final int height = getMeasuredHeight();
mProgressBar.setBounds(0, 0, width, mProgressBarHeight);
if (getChildCount() == 0) {
return;
}
final View child = getChildAt(0);
final int childLeft = getPaddingLeft();
final int childTop = mCurrentTargetOffsetTop + getPaddingTop();
final int childWidth = width - getPaddingLeft() - getPaddingRight();
final int childHeight = height - getPaddingTop() - getPaddingBottom();
child.layout(childLeft, childTop, childLeft + childWidth, childTop + childHeight);
}
#Override
public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
if (getChildCount() > 1 && !isInEditMode()) {
throw new IllegalStateException("SwipeRefreshLayout can host only one direct child");
}
if (getChildCount() > 0) {
getChildAt(0).measure(
MeasureSpec.makeMeasureSpec(
getMeasuredWidth() - getPaddingLeft() - getPaddingRight(),
MeasureSpec.EXACTLY),
MeasureSpec.makeMeasureSpec(
getMeasuredHeight() - getPaddingTop() - getPaddingBottom(),
MeasureSpec.EXACTLY));
}
}
/**
* #return Whether it is possible for the child view of this layout to
* scroll up. Override this if the child view is a custom view.
*/
public boolean canChildScrollUp() {
if (android.os.Build.VERSION.SDK_INT < 14) {
if (mTarget instanceof AbsListView) {
final AbsListView absListView = (AbsListView) mTarget;
return absListView.getChildCount() > 0
&& (absListView.getFirstVisiblePosition() > 0 || absListView.getChildAt(0)
.getTop() < absListView.getPaddingTop());
} else {
return mTarget.getScrollY() > 0;
}
} else {
return ViewCompat.canScrollVertically(mTarget, -1);
}
}
#Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
ensureTarget();
boolean handled = false;
if (mReturningToStart && ev.getAction() == MotionEvent.ACTION_DOWN) {
mReturningToStart = false;
}
if (isEnabled() && !mReturningToStart && !canChildScrollUp()) {
handled = onTouchEvent(ev);
}
return !handled ? super.onInterceptTouchEvent(ev) : handled;
}
#Override
public void requestDisallowInterceptTouchEvent(boolean b) {
// Nope.
}
#Override
public boolean onTouchEvent(MotionEvent event) {
final int action = event.getAction();
boolean handled = false;
switch (action) {
case MotionEvent.ACTION_DOWN:
mCurrPercentage = 0;
mDownEvent = MotionEvent.obtain(event);
mPrevY = mDownEvent.getY();
break;
case MotionEvent.ACTION_MOVE:
if (mDownEvent != null && !mReturningToStart) {
final float eventY = event.getY();
float yDiff = eventY - mDownEvent.getY();
if (yDiff > mTouchSlop) {
// User velocity passed min velocity; trigger a refresh
if (yDiff > mDistanceToTriggerSync) {
// User movement passed distance; trigger a refresh
startRefresh();
handled = true;
break;
} else {
// Just track the user's movement
setTriggerPercentage(
mAccelerateInterpolator.getInterpolation(
yDiff / mDistanceToTriggerSync));
float offsetTop = yDiff;
if (mPrevY > eventY) {
offsetTop = yDiff - mTouchSlop;
}
updateContentOffsetTop((int) (offsetTop));
if (mPrevY > eventY && (mTarget.getTop() < mTouchSlop)) {
// If the user puts the view back at the top, we
// don't need to. This shouldn't be considered
// cancelling the gesture as the user can restart from the top.
removeCallbacks(mCancel);
} else {
updatePositionTimeout();
}
mPrevY = event.getY();
handled = true;
}
}
}
break;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_CANCEL:
if (mDownEvent != null) {
mDownEvent.recycle();
mDownEvent = null;
}
break;
}
return handled;
}
private void startRefresh() {
removeCallbacks(mCancel);
mReturnToStartPosition.run();
setRefreshing(true);
mListener.onRefresh();
}
private void updateContentOffsetTop(int targetTop) {
final int currentTop = mTarget.getTop();
if (targetTop > mDistanceToTriggerSync) {
targetTop = (int) mDistanceToTriggerSync;
} else if (targetTop < 0) {
targetTop = 0;
}
setTargetOffsetTopAndBottom(targetTop - currentTop);
}
private void setTargetOffsetTopAndBottom(int offset) {
mTarget.offsetTopAndBottom(offset);
mCurrentTargetOffsetTop = mTarget.getTop();
}
private void updatePositionTimeout() {
removeCallbacks(mCancel);
postDelayed(mCancel, RETURN_TO_ORIGINAL_POSITION_TIMEOUT);
}
/**
* Classes that wish to be notified when the swipe gesture correctly
* triggers a refresh should implement this interface.
*/
public interface OnRefreshListener {
public void onRefresh();
}
/**
* Simple AnimationListener to avoid having to implement unneeded methods in
* AnimationListeners.
*/
private class BaseAnimationListener implements AnimationListener {
#Override
public void onAnimationStart(Animation animation) {
}
#Override
public void onAnimationEnd(Animation animation) {
}
#Override
public void onAnimationRepeat(Animation animation) {
}
}
}

SwipeRefreshLayout not showing colors at first and only shows when .setRefreshing(false) called

I am making an android app that uses a SwipeRefreshLayout around a RelativeLayout in a fragment in a ViewPager. When I first open the app and swipe to refresh, the refresh disc shows, but it is blank with no colors.
http://i.stack.imgur.com/VzUeB.png
Then, the next time I swipe to refresh, there is no preview of the refresh (the disc does not come down), and when I release, it takes a second to show. I think it only runs when swipeRefreshLayout.setRefreshing(false) is called, and so it only shows for a split second.
This is my code:
swipeRefreshLayout = (SwipeRefreshLayout)view.findViewById(R.id.swipe_container);
swipeRefreshLayout.setColorSchemeResources(R.color.accentColor, R.color.colorPrimary, R.color.colorPrimaryDark);
swipeRefreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
#Override
public void onRefresh() {
TypedValue typed_value = new TypedValue();
getActivity().getTheme().resolveAttribute(android.support.v7.appcompat.R.attr.actionBarSize, typed_value, true);
DisplayMetrics dm = getResources().getDisplayMetrics();
int height = dm.heightPixels;
swipeRefreshLayout.setProgressViewOffset(false, -200, height / 8);
swipeRefreshLayout.post(new Runnable() {
#Override
public void run() {
swipeRefreshLayout.setRefreshing(true);
}
});
try {
result = new GetReadResultTask().execute().get();
} catch (InterruptedException | ExecutionException e) {
e.printStackTrace();
}
if (result != null && connected) {
AlphaAnimation fadeOut = new AlphaAnimation(1.0f, 0.0f);
AlphaAnimation fadeIn = new AlphaAnimation(0.0f, 1.0f);
stepsTextView.setAnimation(fadeOut);
fadeOut.setDuration(1200);
fadeOut.setFillAfter(true);
List<Bucket> buckets = result.getBuckets();
for (int iii = 0; iii < buckets.size(); iii++) {
dumpDataSet(buckets.get(iii).getDataSet(DataType.AGGREGATE_STEP_COUNT_DELTA));
}
stepsTextView.setAnimation(fadeIn);
fadeIn.setDuration(1200);
fadeIn.setFillAfter(true);
series.resetData(data);
}
swipeRefreshLayout.post(new Runnable() {
#Override
public void run() {
swipeRefreshLayout.setRefreshing(false);
}
});
}
});

Use following code for this..
SwipeActivity Activity is as follows..
public class SwipeActivity extends Activity implements OnRefreshListener{
SwipeRefreshLayout swipeLayout;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_swipe);
swipeLayout = (SwipeRefreshLayout) findViewById(R.id.swipe_container);
swipeLayout.setOnRefreshListener(this);
swipeLayout.setColorScheme(android.R.color.holo_blue_bright,
android.R.color.holo_green_light,
android.R.color.holo_orange_light,
android.R.color.holo_red_light);
}
public void onRefresh() {
new Handler().postDelayed(new Runnable() {
#Override public void run() {
swipeLayout.setRefreshing(false);
}
}, 5000);
}
}
SwipeRefreshLayout is follows.
public class SwipeRefreshLayout extends ViewGroup {
private static final long RETURN_TO_ORIGINAL_POSITION_TIMEOUT = 300;
private static final float ACCELERATE_INTERPOLATION_FACTOR = 1.5f;
private static final float DECELERATE_INTERPOLATION_FACTOR = 2f;
private static final float PROGRESS_BAR_HEIGHT = 4;
private static final float MAX_SWIPE_DISTANCE_FACTOR = .6f;
private static final int REFRESH_TRIGGER_DISTANCE = 120;
private SwipeProgressBar mProgressBar; //the thing that shows progress is going
private View mTarget; //the content that gets pulled down
private int mOriginalOffsetTop;
private OnRefreshListener mListener;
private MotionEvent mDownEvent;
private int mFrom;
private boolean mRefreshing = false;
private int mTouchSlop;
private float mDistanceToTriggerSync = -1;
private float mPrevY;
private int mMediumAnimationDuration;
private float mFromPercentage = 0;
private float mCurrPercentage = 0;
private int mProgressBarHeight;
private int mCurrentTargetOffsetTop;
// Target is returning to its start offset because it was cancelled or a
// refresh was triggered.
private boolean mReturningToStart;
private final DecelerateInterpolator mDecelerateInterpolator;
private final AccelerateInterpolator mAccelerateInterpolator;
private static final int[] LAYOUT_ATTRS = new int[] {
android.R.attr.enabled
};
private final Animation mAnimateToStartPosition = new Animation() {
#Override
public void applyTransformation(float interpolatedTime, Transformation t) {
int targetTop = 0;
if (mFrom != mOriginalOffsetTop) {
targetTop = (mFrom + (int)((mOriginalOffsetTop - mFrom) * interpolatedTime));
}
int offset = targetTop - mTarget.getTop();
final int currentTop = mTarget.getTop();
if (offset + currentTop < 0) {
offset = 0 - currentTop;
}
setTargetOffsetTopAndBottom(offset);
}
};
private Animation mShrinkTrigger = new Animation() {
#Override
public void applyTransformation(float interpolatedTime, Transformation t) {
float percent = mFromPercentage + ((0 - mFromPercentage) * interpolatedTime);
mProgressBar.setTriggerPercentage(percent);
}
};
private final AnimationListener mReturnToStartPositionListener = new BaseAnimationListener() {
#Override
public void onAnimationEnd(Animation animation) {
// Once the target content has returned to its start position, reset
// the target offset to 0
mCurrentTargetOffsetTop = 0;
}
};
private final AnimationListener mShrinkAnimationListener = new BaseAnimationListener() {
#Override
public void onAnimationEnd(Animation animation) {
mCurrPercentage = 0;
}
};
private final Runnable mReturnToStartPosition = new Runnable() {
#Override
public void run() {
mReturningToStart = true;
animateOffsetToStartPosition(mCurrentTargetOffsetTop + getPaddingTop(),
mReturnToStartPositionListener);
}
};
// Cancel the refresh gesture and animate everything back to its original state.
private final Runnable mCancel = new Runnable() {
#Override
public void run() {
mReturningToStart = true;
// Timeout fired since the user last moved their finger; animate the
// trigger to 0 and put the target back at its original position
if (mProgressBar != null) {
mFromPercentage = mCurrPercentage;
mShrinkTrigger.setDuration(mMediumAnimationDuration);
mShrinkTrigger.setAnimationListener(mShrinkAnimationListener);
mShrinkTrigger.reset();
mShrinkTrigger.setInterpolator(mDecelerateInterpolator);
startAnimation(mShrinkTrigger);
}
animateOffsetToStartPosition(mCurrentTargetOffsetTop + getPaddingTop(),
mReturnToStartPositionListener);
}
};
/**
* Simple constructor to use when creating a SwipeRefreshLayout from code.
* #param context
*/
public SwipeRefreshLayout(Context context) {
this(context, null);
}
/**
* Constructor that is called when inflating SwipeRefreshLayout from XML.
* #param context
* #param attrs
*/
public SwipeRefreshLayout(Context context, AttributeSet attrs) {
super(context, attrs);
mTouchSlop = ViewConfiguration.get(context).getScaledTouchSlop();
mMediumAnimationDuration = getResources().getInteger(
android.R.integer.config_mediumAnimTime);
setWillNotDraw(false);
mProgressBar = new SwipeProgressBar(this);
final DisplayMetrics metrics = getResources().getDisplayMetrics();
mProgressBarHeight = (int) (metrics.density * PROGRESS_BAR_HEIGHT);
mDecelerateInterpolator = new DecelerateInterpolator(DECELERATE_INTERPOLATION_FACTOR);
mAccelerateInterpolator = new AccelerateInterpolator(ACCELERATE_INTERPOLATION_FACTOR);
final TypedArray a = context.obtainStyledAttributes(attrs, LAYOUT_ATTRS);
setEnabled(a.getBoolean(0, true));
a.recycle();
}
#Override
public void onAttachedToWindow() {
super.onAttachedToWindow();
removeCallbacks(mCancel);
removeCallbacks(mReturnToStartPosition);
}
#Override
public void onDetachedFromWindow() {
super.onDetachedFromWindow();
removeCallbacks(mReturnToStartPosition);
removeCallbacks(mCancel);
}
private void animateOffsetToStartPosition(int from, AnimationListener listener) {
mFrom = from;
mAnimateToStartPosition.reset();
mAnimateToStartPosition.setDuration(mMediumAnimationDuration);
mAnimateToStartPosition.setAnimationListener(listener);
mAnimateToStartPosition.setInterpolator(mDecelerateInterpolator);
mTarget.startAnimation(mAnimateToStartPosition);
}
/**
* Set the listener to be notified when a refresh is triggered via the swipe
* gesture.
*/
public void setOnRefreshListener(SwipeActivity swipeActivity) {
mListener = swipeActivity;
}
private void setTriggerPercentage(float percent) {
if (percent == 0f) {
// No-op. A null trigger means it's uninitialized, and setting it to zero-percent
// means we're trying to reset state, so there's nothing to reset in this case.
mCurrPercentage = 0;
return;
}
mCurrPercentage = percent;
mProgressBar.setTriggerPercentage(percent);
}
/**
* Notify the widget that refresh state has changed. Do not call this when
* refresh is triggered by a swipe gesture.
*
* #param refreshing Whether or not the view should show refresh progress.
*/
public void setRefreshing(boolean refreshing) {
if (mRefreshing != refreshing) {
ensureTarget();
mCurrPercentage = 0;
mRefreshing = refreshing;
if (mRefreshing) {
mProgressBar.start();
} else {
mProgressBar.stop();
}
}
}
/**
* Set the four colors used in the progress animation. The first color will
* also be the color of the bar that grows in response to a user swipe
* gesture.
*
* #param colorRes1 Color resource.
* #param colorRes2 Color resource.
* #param colorRes3 Color resource.
* #param colorRes4 Color resource.
*/
public void setColorScheme(int colorRes1, int colorRes2, int colorRes3, int colorRes4) {
ensureTarget();
final Resources res = getResources();
final int color1 = res.getColor(colorRes1);
final int color2 = res.getColor(colorRes2);
final int color3 = res.getColor(colorRes3);
final int color4 = res.getColor(colorRes4);
mProgressBar.setColorScheme(color1, color2, color3,color4);
}
/**
* #return Whether the SwipeRefreshWidget is actively showing refresh
* progress.
*/
public boolean isRefreshing() {
return mRefreshing;
}
private void ensureTarget() {
// Don't bother getting the parent height if the parent hasn't been laid out yet.
if (mTarget == null) {
if (getChildCount() > 1 && !isInEditMode()) {
throw new IllegalStateException(
"SwipeRefreshLayout can host only one direct child");
}
mTarget = getChildAt(0);
mOriginalOffsetTop = mTarget.getTop() + getPaddingTop();
}
if (mDistanceToTriggerSync == -1) {
if (getParent() != null && ((View)getParent()).getHeight() > 0) {
final DisplayMetrics metrics = getResources().getDisplayMetrics();
mDistanceToTriggerSync = (int) Math.min(
((View) getParent()) .getHeight() * MAX_SWIPE_DISTANCE_FACTOR,
REFRESH_TRIGGER_DISTANCE * metrics.density);
}
}
}
#Override
public void draw(Canvas canvas) {
super.draw(canvas);
mProgressBar.draw(canvas);
}
#Override
protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
final int width = getMeasuredWidth();
final int height = getMeasuredHeight();
mProgressBar.setBounds(0, 0, width, mProgressBarHeight);
if (getChildCount() == 0) {
return;
}
final View child = getChildAt(0);
final int childLeft = getPaddingLeft();
final int childTop = mCurrentTargetOffsetTop + getPaddingTop();
final int childWidth = width - getPaddingLeft() - getPaddingRight();
final int childHeight = height - getPaddingTop() - getPaddingBottom();
child.layout(childLeft, childTop, childLeft + childWidth, childTop + childHeight);
}
#Override
public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
if (getChildCount() > 1 && !isInEditMode()) {
throw new IllegalStateException("SwipeRefreshLayout can host only one direct child");
}
if (getChildCount() > 0) {
getChildAt(0).measure(
MeasureSpec.makeMeasureSpec(
getMeasuredWidth() - getPaddingLeft() - getPaddingRight(),
MeasureSpec.EXACTLY),
MeasureSpec.makeMeasureSpec(
getMeasuredHeight() - getPaddingTop() - getPaddingBottom(),
MeasureSpec.EXACTLY));
}
}
/**
* #return Whether it is possible for the child view of this layout to
* scroll up. Override this if the child view is a custom view.
*/
public boolean canChildScrollUp() {
if (android.os.Build.VERSION.SDK_INT < 14) {
if (mTarget instanceof AbsListView) {
final AbsListView absListView = (AbsListView) mTarget;
return absListView.getChildCount() > 0
&& (absListView.getFirstVisiblePosition() > 0 || absListView.getChildAt(0)
.getTop() < absListView.getPaddingTop());
} else {
return mTarget.getScrollY() > 0;
}
} else {
return ViewCompat.canScrollVertically(mTarget, -1);
}
}
#Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
ensureTarget();
boolean handled = false;
if (mReturningToStart && ev.getAction() == MotionEvent.ACTION_DOWN) {
mReturningToStart = false;
}
if (isEnabled() && !mReturningToStart && !canChildScrollUp()) {
handled = onTouchEvent(ev);
}
return !handled ? super.onInterceptTouchEvent(ev) : handled;
}
#Override
public void requestDisallowInterceptTouchEvent(boolean b) {
// Nope.
}
#Override
public boolean onTouchEvent(MotionEvent event) {
final int action = event.getAction();
boolean handled = false;
switch (action) {
case MotionEvent.ACTION_DOWN:
mCurrPercentage = 0;
mDownEvent = MotionEvent.obtain(event);
mPrevY = mDownEvent.getY();
break;
case MotionEvent.ACTION_MOVE:
if (mDownEvent != null && !mReturningToStart) {
final float eventY = event.getY();
float yDiff = eventY - mDownEvent.getY();
if (yDiff > mTouchSlop) {
// User velocity passed min velocity; trigger a refresh
if (yDiff > mDistanceToTriggerSync) {
// User movement passed distance; trigger a refresh
startRefresh();
handled = true;
break;
} else {
// Just track the user's movement
setTriggerPercentage(
mAccelerateInterpolator.getInterpolation(
yDiff / mDistanceToTriggerSync));
float offsetTop = yDiff;
if (mPrevY > eventY) {
offsetTop = yDiff - mTouchSlop;
}
updateContentOffsetTop((int) (offsetTop));
if (mPrevY > eventY && (mTarget.getTop() < mTouchSlop)) {
// If the user puts the view back at the top, we
// don't need to. This shouldn't be considered
// cancelling the gesture as the user can restart from the top.
removeCallbacks(mCancel);
} else {
updatePositionTimeout();
}
mPrevY = event.getY();
handled = true;
}
}
}
break;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_CANCEL:
if (mDownEvent != null) {
mDownEvent.recycle();
mDownEvent = null;
}
break;
}
return handled;
}
private void startRefresh() {
removeCallbacks(mCancel);
mReturnToStartPosition.run();
setRefreshing(true);
mListener.onRefresh();
}
private void updateContentOffsetTop(int targetTop) {
final int currentTop = mTarget.getTop();
if (targetTop > mDistanceToTriggerSync) {
targetTop = (int) mDistanceToTriggerSync;
} else if (targetTop < 0) {
targetTop = 0;
}
setTargetOffsetTopAndBottom(targetTop - currentTop);
}
private void setTargetOffsetTopAndBottom(int offset) {
mTarget.offsetTopAndBottom(offset);
mCurrentTargetOffsetTop = mTarget.getTop();
}
private void updatePositionTimeout() {
removeCallbacks(mCancel);
postDelayed(mCancel, RETURN_TO_ORIGINAL_POSITION_TIMEOUT);
}
/**
* Classes that wish to be notified when the swipe gesture correctly
* triggers a refresh should implement this interface.
*/
public interface OnRefreshListener {
public void onRefresh();
}
/**
* Simple AnimationListener to avoid having to implement unneeded methods in
* AnimationListeners.
*/
private class BaseAnimationListener implements AnimationListener {
#Override
public void onAnimationStart(Animation animation) {
}
#Override
public void onAnimationEnd(Animation animation) {
}
#Override
public void onAnimationRepeat(Animation animation) {
}
}
}
following is manifest file..
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.swiperefreshlayout"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="17" />
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name="com.example.swiperefreshlayout.SwipeActivity"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
Just copy paste all code in your project and you will get your desired output.

Unable to start activity with java.lang.NullPointerException on Fling

When I am trying to fling example this error faced. with java Null pointer exception.
My java code
public class LearnCount extends Activity {
private FlingGallery mGallery;
public boolean onTouchEvent(MotionEvent event) {
return mGallery.onGalleryTouchEvent(event);
}
private String[] teststr = {
"test1","test2","test3","test4","test5"
};
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
setContentView(R.layout.main);
LinearLayout productHolder = (LinearLayout) findViewById(R.id.linearLayoutOfCount);
mGallery = new FlingGallery(this);
mGallery.setAdapter(new ArrayAdapter<String>(getApplicationContext(),
android.R.layout.simple_list_item_1, teststr) {
public View getView(int position, View convertView, ViewGroup parent) {
System.out.println(mGallery.getCurrentPosition() + " position");
if (convertView != null
&& convertView instanceof GalleryViewItem) {
GalleryViewItem galleryView = (GalleryViewItem) convertView;
//galleryView.pImage.setImageResource(mImageIds[position]);
galleryView.b.setText(teststr[position]);
return galleryView;
}
GalleryViewItem gvi = new GalleryViewItem(getApplicationContext(), position);
gvi.b.setText(teststr[position]);
return gvi;
}
});
productHolder.addView(mGallery);
}
public class GalleryViewItem extends TableLayout {
private TextView b;
public GalleryViewItem(Context context, int position) {
super(context);
LayoutInflater inflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View v = inflater.inflate(R.layout.test, null);
b = (TextView) v.findViewById(R.id.test);
this.addView(v);
}
}
public class FlingGallery extends FrameLayout {
// Constants
private final int swipe_min_distance = 120;
private final int swipe_max_off_path = 250;
private final int swipe_threshold_veloicty = 400;
// Properties
private int mViewPaddingWidth = 0;
private int mAnimationDuration = 250;
private float mSnapBorderRatio = 0.5f;
private boolean mIsGalleryCircular = false;
// Members
private int mGalleryWidth = 0;
private boolean mIsTouched = false;
private boolean mIsDragging = false;
private float mCurrentOffset = 0.0f;
private long mScrollTimestamp = 0;
private int mFlingDirection = 0;
public int mCurrentPosition = 0;
private int mCurrentViewNumber = 0;
private Context mContext;
private Adapter mAdapter;
private FlingGalleryView[] mViews;
private FlingGalleryAnimation mAnimation;
private GestureDetector mGestureDetector;
private Interpolator mDecelerateInterpolater;
public FlingGallery(Context context) {
super(context);
mContext = context;
mAdapter = null;
mViews = new FlingGalleryView[3];
mViews[0] = new FlingGalleryView(0, this);
mViews[1] = new FlingGalleryView(1, this);
mViews[2] = new FlingGalleryView(2, this);
mAnimation = new FlingGalleryAnimation();
mGestureDetector = new GestureDetector(new FlingGestureDetector());
mDecelerateInterpolater = AnimationUtils.loadInterpolator(mContext,
android.R.anim.decelerate_interpolator);
}
public void setPaddingWidth(int viewPaddingWidth) {
mViewPaddingWidth = viewPaddingWidth;
}
public void setAnimationDuration(int animationDuration) {
mAnimationDuration = animationDuration;
}
public void setSnapBorderRatio(float snapBorderRatio) {
mSnapBorderRatio = snapBorderRatio;
}
public int getCurrentPosition() {
return mCurrentPosition;
}
public void setIsGalleryCircular(boolean isGalleryCircular) {
if (mIsGalleryCircular != isGalleryCircular) {
mIsGalleryCircular = isGalleryCircular;
if (mCurrentPosition == getFirstPosition()) {
// We need to reload the view immediately to the left to
// change it to circular view or blank
mViews[getPrevViewNumber(mCurrentViewNumber)]
.recycleView(getPrevPosition(mCurrentPosition));
}
if (mCurrentPosition == getLastPosition()) {
// We need to reload the view immediately to the right to
// change it to circular view or blank
mViews[getNextViewNumber(mCurrentViewNumber)]
.recycleView(getNextPosition(mCurrentPosition));
}
}
}
public int getGalleryCount() {
return (mAdapter == null) ? 0 : mAdapter.getCount();
}
public int getFirstPosition() {
return 0;
}
public int getLastPosition() {
return (getGalleryCount() == 0) ? 0 : getGalleryCount() - 1;
}
private int getPrevPosition(int relativePosition) {
int prevPosition = relativePosition - 1;
if (prevPosition < getFirstPosition()) {
prevPosition = getFirstPosition() - 1;
if (mIsGalleryCircular == true) {
prevPosition = getLastPosition();
}
}
return prevPosition;
}
private int getNextPosition(int relativePosition) {
int nextPosition = relativePosition + 1;
if (nextPosition > getLastPosition()) {
nextPosition = getLastPosition() + 1;
if (mIsGalleryCircular == true) {
nextPosition = getFirstPosition();
}
}
return nextPosition;
}
private int getPrevViewNumber(int relativeViewNumber) {
return (relativeViewNumber == 0) ? 2 : relativeViewNumber - 1;
}
private int getNextViewNumber(int relativeViewNumber) {
return (relativeViewNumber == 2) ? 0 : relativeViewNumber + 1;
}
protected void onLayout(boolean changed, int left, int top, int right,
int bottom) {
super.onLayout(changed, left, top, right, bottom);
// Calculate our view width
mGalleryWidth = right - left;
if (changed == true) {
// Position views at correct starting offsets
mViews[0].setOffset(0, 0, mCurrentViewNumber);
mViews[1].setOffset(0, 0, mCurrentViewNumber);
mViews[2].setOffset(0, 0, mCurrentViewNumber);
}
}
public void setAdapter(Adapter adapter) {
mAdapter = adapter;
mCurrentPosition = 0;
mCurrentViewNumber = 0;
// Load the initial views from adapter
mViews[0].recycleView(mCurrentPosition);
mViews[1].recycleView(getNextPosition(mCurrentPosition));
mViews[2].recycleView(getPrevPosition(mCurrentPosition));
// Position views at correct starting offsets
mViews[0].setOffset(0, 0, mCurrentViewNumber);
mViews[1].setOffset(0, 0, mCurrentViewNumber);
mViews[2].setOffset(0, 0, mCurrentViewNumber);
}
private int getViewOffset(int viewNumber, int relativeViewNumber) {
// Determine width including configured padding width
int offsetWidth = mGalleryWidth + mViewPaddingWidth;
// Position the previous view one measured width to left
if (viewNumber == getPrevViewNumber(relativeViewNumber)) {
return offsetWidth;
}
// Position the next view one measured width to the right
if (viewNumber == getNextViewNumber(relativeViewNumber)) {
return offsetWidth * -1;
}
return 0;
}
void movePrevious() {
// Slide to previous view
mFlingDirection = 1;
processGesture();
}
void moveNext() {
// Slide to next view
mFlingDirection = -1;
processGesture();
}
public boolean onKeyDown(int keyCode, KeyEvent event) {
switch (keyCode) {
case KeyEvent.KEYCODE_DPAD_LEFT:
movePrevious();
return true;
case KeyEvent.KEYCODE_DPAD_RIGHT:
moveNext();
return true;
case KeyEvent.KEYCODE_DPAD_CENTER:
case KeyEvent.KEYCODE_ENTER:
}
return super.onKeyDown(keyCode, event);
}
public boolean onGalleryTouchEvent(MotionEvent event) {
boolean consumed = mGestureDetector.onTouchEvent(event);
if (event.getAction() == MotionEvent.ACTION_UP) {
if (mIsTouched || mIsDragging) {
processScrollSnap();
processGesture();
}
}
return consumed;
}
void processGesture() {
int newViewNumber = mCurrentViewNumber;
int reloadViewNumber = 0;
int reloadPosition = 0;
mIsTouched = false;
mIsDragging = false;
if (mFlingDirection > 0) {
if (mCurrentPosition > getFirstPosition()
|| mIsGalleryCircular == true) {
// Determine previous view and outgoing view to recycle
newViewNumber = getPrevViewNumber(mCurrentViewNumber);
mCurrentPosition = getPrevPosition(mCurrentPosition);
reloadViewNumber = getNextViewNumber(mCurrentViewNumber);
reloadPosition = getPrevPosition(mCurrentPosition);
}
}
if (mFlingDirection < 0) {
if (mCurrentPosition < getLastPosition()
|| mIsGalleryCircular == true) {
// Determine the next view and outgoing view to recycle
newViewNumber = getNextViewNumber(mCurrentViewNumber);
mCurrentPosition = getNextPosition(mCurrentPosition);
reloadViewNumber = getPrevViewNumber(mCurrentViewNumber);
reloadPosition = getNextPosition(mCurrentPosition);
}
}
if (newViewNumber != mCurrentViewNumber) {
mCurrentViewNumber = newViewNumber;
// Reload outgoing view from adapter in new position
mViews[reloadViewNumber].recycleView(reloadPosition);
}
// Ensure input focus on the current view
mViews[mCurrentViewNumber].requestFocus();
// Run the slide animations for view transitions
mAnimation.prepareAnimation(mCurrentViewNumber);
this.startAnimation(mAnimation);
// Reset fling state
mFlingDirection = 0;
//checkNextBackButton(mCurrentPosition);
System.out.println("positionFiling" + mCurrentPosition);
}
void processScrollSnap() {
// Snap to next view if scrolled passed snap position
float rollEdgeWidth = mGalleryWidth * mSnapBorderRatio;
int rollOffset = mGalleryWidth - (int) rollEdgeWidth;
int currentOffset = mViews[mCurrentViewNumber].getCurrentOffset();
if (currentOffset <= rollOffset * -1) {
// Snap to previous view
mFlingDirection = 1;
}
if (currentOffset >= rollOffset) {
// Snap to next view
mFlingDirection = -1;
}
}
public class FlingGalleryView {
private int mViewNumber;
private FrameLayout mParentLayout;
private FrameLayout mInvalidLayout = null;
private LinearLayout mInternalLayout = null;
private View mExternalView = null;
public FlingGalleryView(int viewNumber, FrameLayout parentLayout) {
mViewNumber = viewNumber;
mParentLayout = parentLayout;
// Invalid layout is used when outside gallery
mInvalidLayout = new FrameLayout(mContext);
mInvalidLayout.setLayoutParams(new LinearLayout.LayoutParams(
LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT));
// Internal layout is permanent for duration
mInternalLayout = new LinearLayout(mContext);
mInternalLayout.setLayoutParams(new LinearLayout.LayoutParams(
LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT));
mParentLayout.addView(mInternalLayout);
}
public void recycleView(int newPosition) {
if (mExternalView != null) {
mInternalLayout.removeView(mExternalView);
}
if (mAdapter != null) {
if (newPosition >= getFirstPosition()
&& newPosition <= getLastPosition()) {
mExternalView = mAdapter.getView(newPosition,
mExternalView, mInternalLayout);
} else {
mExternalView = mInvalidLayout;
}
}
if (mExternalView != null) {
mInternalLayout.addView(mExternalView,
new LinearLayout.LayoutParams(
LayoutParams.FILL_PARENT,
LayoutParams.FILL_PARENT));
}
}
public void setOffset(int xOffset, int yOffset,
int relativeViewNumber) {
// Scroll the target view relative to its own position relative
// to currently displayed view
mInternalLayout.scrollTo(getViewOffset(mViewNumber,
relativeViewNumber)
+ xOffset, yOffset);
}
public int getCurrentOffset() {
// Return the current scroll position
return mInternalLayout.getScrollX();
}
public void requestFocus() {
mInternalLayout.requestFocus();
}
}
public class FlingGalleryAnimation extends Animation {
private boolean mIsAnimationInProgres;
private int mRelativeViewNumber;
private int mInitialOffset;
private int mTargetOffset;
private int mTargetDistance;
public FlingGalleryAnimation() {
mIsAnimationInProgres = false;
mRelativeViewNumber = 0;
mInitialOffset = 0;
mTargetOffset = 0;
mTargetDistance = 0;
}
public void prepareAnimation(int relativeViewNumber) {
// If we are animating relative to a new view
if (mRelativeViewNumber != relativeViewNumber) {
if (mIsAnimationInProgres == true) {
// We only have three views so if requested again to
// animate in same direction we must snap
int newDirection = (relativeViewNumber == getPrevViewNumber(mRelativeViewNumber)) ? 1
: -1;
int animDirection = (mTargetDistance < 0) ? 1 : -1;
// If animation in same direction
if (animDirection == newDirection) {
// Ran out of time to animate so snap to the target
// offset
mViews[0].setOffset(mTargetOffset, 0,
mRelativeViewNumber);
mViews[1].setOffset(mTargetOffset, 0,
mRelativeViewNumber);
mViews[2].setOffset(mTargetOffset, 0,
mRelativeViewNumber);
}
}
// Set relative view number for animation
mRelativeViewNumber = relativeViewNumber;
}
// Note: In this implementation the targetOffset will always be
// zero
// as we are centering the view; but we include the calculations
// of
// targetOffset and targetDistance for use in future
// implementations
mInitialOffset = mViews[mRelativeViewNumber].getCurrentOffset();
mTargetOffset = getViewOffset(mRelativeViewNumber,
mRelativeViewNumber);
mTargetDistance = mTargetOffset - mInitialOffset;
// Configure base animation properties
this.setDuration(mAnimationDuration);
this.setInterpolator(mDecelerateInterpolater);
// Start/continued animation
mIsAnimationInProgres = true;
}
protected void applyTransformation(float interpolatedTime,
Transformation transformation) {
// Ensure interpolatedTime does not over-shoot then calculate
// new offset
interpolatedTime = (interpolatedTime > 1.0f) ? 1.0f
: interpolatedTime;
int offset = mInitialOffset
+ (int) (mTargetDistance * interpolatedTime);
for (int viewNumber = 0; viewNumber < 3; viewNumber++) {
// Only need to animate the visible views as the other view
// will always be off-screen
if ((mTargetDistance > 0 && viewNumber != getNextViewNumber(mRelativeViewNumber))
|| (mTargetDistance < 0 && viewNumber != getPrevViewNumber(mRelativeViewNumber))) {
mViews[viewNumber].setOffset(offset, 0,
mRelativeViewNumber);
}
}
}
public boolean getTransformation(long currentTime,
Transformation outTransformation) {
if (super.getTransformation(currentTime, outTransformation) == false) {
// Perform final adjustment to offsets to cleanup animation
mViews[0].setOffset(mTargetOffset, 0, mRelativeViewNumber);
mViews[1].setOffset(mTargetOffset, 0, mRelativeViewNumber);
mViews[2].setOffset(mTargetOffset, 0, mRelativeViewNumber);
// Reached the animation target
mIsAnimationInProgres = false;
return false;
}
// Cancel if the screen touched
if (mIsTouched || mIsDragging) {
// Note that at this point we still consider ourselves to be
// animating
// because we have not yet reached the target offset; its
// just that the
// user has temporarily interrupted the animation with a
// touch gesture
return false;
}
return true;
}
}
private class FlingGestureDetector extends GestureDetector.SimpleOnGestureListener {
public boolean onDown(MotionEvent e) {
// Stop animation
mIsTouched = true;
// Reset fling state
mFlingDirection = 0;
return true;
}
public boolean onScroll(MotionEvent e1, MotionEvent e2,
float distanceX, float distanceY) {
if (e2.getAction() == MotionEvent.ACTION_MOVE) {
if (mIsDragging == false) {
// Stop animation
mIsTouched = true;
// Reconfigure scroll
mIsDragging = true;
mFlingDirection = 0;
mScrollTimestamp = System.currentTimeMillis();
mCurrentOffset = mViews[mCurrentViewNumber]
.getCurrentOffset();
}
float maxVelocity = mGalleryWidth
/ (mAnimationDuration / 1000.0f);
long timestampDelta = System.currentTimeMillis()
- mScrollTimestamp;
float maxScrollDelta = maxVelocity
* (timestampDelta / 1000.0f);
float currentScrollDelta = e1.getX() - e2.getX();
if (currentScrollDelta < maxScrollDelta * -1)
currentScrollDelta = maxScrollDelta * -1;
if (currentScrollDelta > maxScrollDelta)
currentScrollDelta = maxScrollDelta;
int scrollOffset = Math.round(mCurrentOffset
+ currentScrollDelta);
// We can't scroll more than the width of our own frame
// layout
if (scrollOffset >= mGalleryWidth)
scrollOffset = mGalleryWidth;
if (scrollOffset <= mGalleryWidth * -1)
scrollOffset = mGalleryWidth * -1;
mViews[0].setOffset(scrollOffset, 0, mCurrentViewNumber);
mViews[1].setOffset(scrollOffset, 0, mCurrentViewNumber);
mViews[2].setOffset(scrollOffset, 0, mCurrentViewNumber);
}
return false;
}
public boolean onFling(MotionEvent e1, MotionEvent e2,
float velocityX, float velocityY) {
if (Math.abs(e1.getY() - e2.getY()) <= swipe_max_off_path) {
if (e2.getX() - e1.getX() > swipe_min_distance
&& Math.abs(velocityX) > swipe_threshold_veloicty) {
movePrevious();
}
if (e1.getX() - e2.getX() > swipe_min_distance
&& Math.abs(velocityX) > swipe_threshold_veloicty) {
moveNext();
}
}
return false;
}
public void onLongPress(MotionEvent e) {
// Finalise scrolling
mFlingDirection = 0;
processGesture();
}
public void onShowPress(MotionEvent e) {
}
public boolean onSingleTapUp(MotionEvent e) {
// Reset fling state
mFlingDirection = 0;
return false;
}
}
}
}
My log cat error message is:
I am the beginner for android, something wrong my code?

LinearLayout productHolder = (LinearLayout) findViewById(R.id.linearLayoutOfCount);
Is returning null. Make sure you are referencing the correct id.

Fast Scroll display problem with ListAdapter and SectionIndexer

I have a list of events which are seperated by month and year (Jun 2010, Jul 2010 etc.). I have enabled fast scrolling because the list is really long. I've also implemented SectionIndexer so that people can see what month and year they are currently viewing when scrolling down the list of events at speed.
I don't have any problem with the implementation, just how the information is shown. Fast scrolling with SectionIndexer seems to only really be able to support a label with a single letter. If the list was alphabetised this would be perfect, however I want it to display a bit more text.
If you look at the screenshot bellow you'll see the problem I'm having.
(source: matto1990.com)
What I want to know is: is it possible to change how the text in the centre of the screen is displayed. Can I change it somehow to make it look right (with the background covering all of the text).
Thanks in advance. If you need any clarification, or code just ask.

EDIT: Full sample code for this solution available here.
I had this same problem - I needed to display full text in the overlay rectangle rather than just a single character. I managed to solve it using the following code as an example: http://code.google.com/p/apps-for-android/source/browse/trunk/RingsExtended/src/com/example/android/rings_extended/FastScrollView.java
The author said that this was copied from the Contacts app, which apparently uses its own implementation rather than just setting fastScrollEnabled="true" on the ListView. I altered it a little bit so that you can customize the overlay rectangle width, overlay rectangle height, overlay text size, and scroll thumb width.
For the record, the final result looks like this: http://nolanwlawson.files.wordpress.com/2011/03/pokedroid_1.png
All you need to do is add these values to your res/values/attrs.xml:
<declare-styleable name="CustomFastScrollView">
<attr name="overlayWidth" format="dimension"/>
<attr name="overlayHeight" format="dimension"/>
<attr name="overlayTextSize" format="dimension"/>
<attr name="overlayScrollThumbWidth" format="dimension"/>
</declare-styleable>
And then use this CustomFastScrollView instead of the one in the link:
public class CustomFastScrollView extends FrameLayout
implements OnScrollListener, OnHierarchyChangeListener {
private Drawable mCurrentThumb;
private Drawable mOverlayDrawable;
private int mThumbH;
private int mThumbW;
private int mThumbY;
private RectF mOverlayPos;
// custom values I defined
private int mOverlayWidth;
private int mOverlayHeight;
private float mOverlayTextSize;
private int mOverlayScrollThumbWidth;
private boolean mDragging;
private ListView mList;
private boolean mScrollCompleted;
private boolean mThumbVisible;
private int mVisibleItem;
private Paint mPaint;
private int mListOffset;
private Object [] mSections;
private String mSectionText;
private boolean mDrawOverlay;
private ScrollFade mScrollFade;
private Handler mHandler = new Handler();
private BaseAdapter mListAdapter;
private boolean mChangedBounds;
public static interface SectionIndexer {
Object[] getSections();
int getPositionForSection(int section);
int getSectionForPosition(int position);
}
public CustomFastScrollView(Context context) {
super(context);
init(context, null);
}
public CustomFastScrollView(Context context, AttributeSet attrs) {
super(context, attrs);
init(context, attrs);
}
public CustomFastScrollView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
init(context, attrs);
}
private void useThumbDrawable(Drawable drawable) {
mCurrentThumb = drawable;
mThumbW = mOverlayScrollThumbWidth;//mCurrentThumb.getIntrinsicWidth();
mThumbH = mCurrentThumb.getIntrinsicHeight();
mChangedBounds = true;
}
private void init(Context context, AttributeSet attrs) {
// set all attributes from xml
if (attrs != null) {
TypedArray typedArray = context.obtainStyledAttributes(attrs,
R.styleable.CustomFastScrollView);
mOverlayHeight = typedArray.getDimensionPixelSize(
R.styleable.CustomFastScrollView_overlayHeight, 0);
mOverlayWidth = typedArray.getDimensionPixelSize(
R.styleable.CustomFastScrollView_overlayWidth, 0);
mOverlayTextSize = typedArray.getDimensionPixelSize(
R.styleable.CustomFastScrollView_overlayTextSize, 0);
mOverlayScrollThumbWidth = typedArray.getDimensionPixelSize(
R.styleable.CustomFastScrollView_overlayScrollThumbWidth, 0);
}
// Get both the scrollbar states drawables
final Resources res = context.getResources();
Drawable thumbDrawable = res.getDrawable(R.drawable.scrollbar_handle_accelerated_anim2);
useThumbDrawable(thumbDrawable);
mOverlayDrawable = res.getDrawable(android.R.drawable.alert_dark_frame);
mScrollCompleted = true;
setWillNotDraw(false);
// Need to know when the ListView is added
setOnHierarchyChangeListener(this);
mOverlayPos = new RectF();
mScrollFade = new ScrollFade();
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setTextAlign(Paint.Align.CENTER);
mPaint.setTextSize(mOverlayTextSize);
mPaint.setColor(0xFFFFFFFF);
mPaint.setStyle(Paint.Style.FILL_AND_STROKE);
}
private void removeThumb() {
mThumbVisible = false;
// Draw one last time to remove thumb
invalidate();
}
#Override
public void draw(Canvas canvas) {
super.draw(canvas);
if (!mThumbVisible) {
// No need to draw the rest
return;
}
final int y = mThumbY;
final int viewWidth = getWidth();
final CustomFastScrollView.ScrollFade scrollFade = mScrollFade;
int alpha = -1;
if (scrollFade.mStarted) {
alpha = scrollFade.getAlpha();
if (alpha < ScrollFade.ALPHA_MAX / 2) {
mCurrentThumb.setAlpha(alpha * 2);
}
int left = viewWidth - (mThumbW * alpha) / ScrollFade.ALPHA_MAX;
mCurrentThumb.setBounds(left, 0, viewWidth, mThumbH);
mChangedBounds = true;
}
canvas.translate(0, y);
mCurrentThumb.draw(canvas);
canvas.translate(0, -y);
// If user is dragging the scroll bar, draw the alphabet overlay
if (mDragging && mDrawOverlay) {
mOverlayDrawable.draw(canvas);
final Paint paint = mPaint;
float descent = paint.descent();
final RectF rectF = mOverlayPos;
canvas.drawText(mSectionText, (int) (rectF.left + rectF.right) / 2,
(int) (rectF.bottom + rectF.top) / 2 + descent, paint);
} else if (alpha == 0) {
scrollFade.mStarted = false;
removeThumb();
} else {
invalidate(viewWidth - mThumbW, y, viewWidth, y + mThumbH);
}
}
#Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
if (mCurrentThumb != null) {
mCurrentThumb.setBounds(w - mThumbW, 0, w, mThumbH);
}
final RectF pos = mOverlayPos;
pos.left = (w - mOverlayWidth) / 2;
pos.right = pos.left + mOverlayWidth;
pos.top = h / 10; // 10% from top
pos.bottom = pos.top + mOverlayHeight;
mOverlayDrawable.setBounds((int) pos.left, (int) pos.top,
(int) pos.right, (int) pos.bottom);
}
public void onScrollStateChanged(AbsListView view, int scrollState) {
}
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount,
int totalItemCount) {
if (totalItemCount - visibleItemCount > 0 && !mDragging) {
mThumbY = ((getHeight() - mThumbH) * firstVisibleItem) / (totalItemCount - visibleItemCount);
if (mChangedBounds) {
final int viewWidth = getWidth();
mCurrentThumb.setBounds(viewWidth - mThumbW, 0, viewWidth, mThumbH);
mChangedBounds = false;
}
}
mScrollCompleted = true;
if (firstVisibleItem == mVisibleItem) {
return;
}
mVisibleItem = firstVisibleItem;
if (!mThumbVisible || mScrollFade.mStarted) {
mThumbVisible = true;
mCurrentThumb.setAlpha(ScrollFade.ALPHA_MAX);
}
mHandler.removeCallbacks(mScrollFade);
mScrollFade.mStarted = false;
if (!mDragging) {
mHandler.postDelayed(mScrollFade, 1500);
}
}
private void getSections() {
Adapter adapter = mList.getAdapter();
if (adapter instanceof HeaderViewListAdapter) {
mListOffset = ((HeaderViewListAdapter)adapter).getHeadersCount();
adapter = ((HeaderViewListAdapter)adapter).getWrappedAdapter();
}
if (adapter instanceof SectionIndexer) {
mListAdapter = (BaseAdapter) adapter;
mSections = ((SectionIndexer) mListAdapter).getSections();
}
}
public void onChildViewAdded(View parent, View child) {
if (child instanceof ListView) {
mList = (ListView)child;
mList.setOnScrollListener(this);
getSections();
}
}
public void onChildViewRemoved(View parent, View child) {
if (child == mList) {
mList = null;
mListAdapter = null;
mSections = null;
}
}
#Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
if (mThumbVisible && ev.getAction() == MotionEvent.ACTION_DOWN) {
if (ev.getX() > getWidth() - mThumbW && ev.getY() >= mThumbY &&
ev.getY() <= mThumbY + mThumbH) {
mDragging = true;
return true;
}
}
return false;
}
private void scrollTo(float position) {
int count = mList.getCount();
mScrollCompleted = false;
final Object[] sections = mSections;
int sectionIndex;
if (sections != null && sections.length > 1) {
final int nSections = sections.length;
int section = (int) (position * nSections);
if (section >= nSections) {
section = nSections - 1;
}
sectionIndex = section;
final SectionIndexer baseAdapter = (SectionIndexer) mListAdapter;
int index = baseAdapter.getPositionForSection(section);
// Given the expected section and index, the following code will
// try to account for missing sections (no names starting with..)
// It will compute the scroll space of surrounding empty sections
// and interpolate the currently visible letter's range across the
// available space, so that there is always some list movement while
// the user moves the thumb.
int nextIndex = count;
int prevIndex = index;
int prevSection = section;
int nextSection = section + 1;
// Assume the next section is unique
if (section < nSections - 1) {
nextIndex = baseAdapter.getPositionForSection(section + 1);
}
// Find the previous index if we're slicing the previous section
if (nextIndex == index) {
// Non-existent letter
while (section > 0) {
section--;
prevIndex = baseAdapter.getPositionForSection(section);
if (prevIndex != index) {
prevSection = section;
sectionIndex = section;
break;
}
}
}
// Find the next index, in case the assumed next index is not
// unique. For instance, if there is no P, then request for P's
// position actually returns Q's. So we need to look ahead to make
// sure that there is really a Q at Q's position. If not, move
// further down...
int nextNextSection = nextSection + 1;
while (nextNextSection < nSections &&
baseAdapter.getPositionForSection(nextNextSection) == nextIndex) {
nextNextSection++;
nextSection++;
}
// Compute the beginning and ending scroll range percentage of the
// currently visible letter. This could be equal to or greater than
// (1 / nSections).
float fPrev = (float) prevSection / nSections;
float fNext = (float) nextSection / nSections;
index = prevIndex + (int) ((nextIndex - prevIndex) * (position - fPrev)
/ (fNext - fPrev));
// Don't overflow
if (index > count - 1) index = count - 1;
mList.setSelectionFromTop(index + mListOffset, 0);
} else {
int index = (int) (position * count);
mList.setSelectionFromTop(index + mListOffset, 0);
sectionIndex = -1;
}
if (sectionIndex >= 0) {
String text = mSectionText = sections[sectionIndex].toString();
mDrawOverlay = (text.length() != 1 || text.charAt(0) != ' ') &&
sectionIndex < sections.length;
} else {
mDrawOverlay = false;
}
}
private void cancelFling() {
// Cancel the list fling
MotionEvent cancelFling = MotionEvent.obtain(0, 0, MotionEvent.ACTION_CANCEL, 0, 0, 0);
mList.onTouchEvent(cancelFling);
cancelFling.recycle();
}
#Override
public boolean onTouchEvent(MotionEvent me) {
if (me.getAction() == MotionEvent.ACTION_DOWN) {
if (me.getX() > getWidth() - mThumbW
&& me.getY() >= mThumbY
&& me.getY() <= mThumbY + mThumbH) {
mDragging = true;
if (mListAdapter == null && mList != null) {
getSections();
}
cancelFling();
return true;
}
} else if (me.getAction() == MotionEvent.ACTION_UP) {
if (mDragging) {
mDragging = false;
final Handler handler = mHandler;
handler.removeCallbacks(mScrollFade);
handler.postDelayed(mScrollFade, 1000);
return true;
}
} else if (me.getAction() == MotionEvent.ACTION_MOVE) {
if (mDragging) {
final int viewHeight = getHeight();
mThumbY = (int) me.getY() - mThumbH + 10;
if (mThumbY < 0) {
mThumbY = 0;
} else if (mThumbY + mThumbH > viewHeight) {
mThumbY = viewHeight - mThumbH;
}
// If the previous scrollTo is still pending
if (mScrollCompleted) {
scrollTo((float) mThumbY / (viewHeight - mThumbH));
}
return true;
}
}
return super.onTouchEvent(me);
}
public class ScrollFade implements Runnable {
long mStartTime;
long mFadeDuration;
boolean mStarted;
static final int ALPHA_MAX = 200;
static final long FADE_DURATION = 200;
void startFade() {
mFadeDuration = FADE_DURATION;
mStartTime = SystemClock.uptimeMillis();
mStarted = true;
}
int getAlpha() {
if (!mStarted) {
return ALPHA_MAX;
}
int alpha;
long now = SystemClock.uptimeMillis();
if (now > mStartTime + mFadeDuration) {
alpha = 0;
} else {
alpha = (int) (ALPHA_MAX - ((now - mStartTime) * ALPHA_MAX) / mFadeDuration);
}
return alpha;
}
public void run() {
if (!mStarted) {
startFade();
invalidate();
}
if (getAlpha() > 0) {
final int y = mThumbY;
final int viewWidth = getWidth();
invalidate(viewWidth - mThumbW, y, viewWidth, y + mThumbH);
} else {
mStarted = false;
removeThumb();
}
}
}
}
You can also tweak the translucency of the scroll thumb using ALPHA_MAX.
Then put something like this in your layout xml file:
<com.myapp.CustomFastScrollView android:layout_width="wrap_content"
android:layout_height="fill_parent"
myapp:overlayWidth="175dp" myapp:overlayHeight="110dp" myapp:overlayTextSize="36dp"
myapp:overlayScrollThumbWidth="60dp" android:id="#+id/fast_scroll_view">
<ListView android:id="#android:id/list" android:layout_width="wrap_content"
android:layout_height="fill_parent"/>
<TextView android:id="#android:id/empty"
android:layout_width="wrap_content" android:layout_height="wrap_content"
android:text="" />
</com.myapp.CustomFastScrollView>
Don't forget to declare your attributes in that layout xml file as well:
... xmlns:myapp= "http://schemas.android.com/apk/res/com.myapp" ...
You'll also need to grab the R.drawable.scrollbar_handle_accelerated_anim2 drawables from that Android source code. The link above only contains the mdpi one.

The FastScroller widget is responsible for drawing the overlay. You should probably take a look at its source:
https://android.googlesource.com/platform/frameworks/base/+/gingerbread-release/core/java/android/widget/FastScroller.java
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// If user is dragging the scroll bar, draw the alphabet overlay