Android fragment blank - android

I have a fragment which has RelativeLayout and a ImageView.
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/pagelayout"
android:layout_below="#layout/toolbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:background="#color/aqua_blue"
tools:context="MainActivityFragment">
<ImageView
android:id="#+id/pdfImage"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#android:color/white"
android:adjustViewBounds="true"
android:scaleType="fitStart"/>
I render a pdfpage as an image and display in the image view in onViewCreated as follows.
pageLayout = (RelativeLayout) rootView.findViewById(R.id.pagelayout);
//Retain view references.
mImageView = (ImageView) rootView.findViewById(R.id.pdfImage);
// Show the first page by default.
mCurrentPageNum = pdfRenderer.getmCurrentPageNum();
if (mCurrentPageNum == 0) {
mCurrentPageNum = 1;
pdfRenderer.setmCurrentPageNum(mCurrentPageNum);
}
showPage(mCurrentPageNum, true, this.activity);
//get screen size
DisplayMetrics metrics = context.getResources().getDisplayMetrics();
scrwidth = metrics.widthPixels;
scrheight = pdfRenderer.getPDFImage().getHeight();
pageControlsList = pdfRenderer.GetPageControls();
if (pageControlsList != null) {
if (pageControlsList.size() > 0) {
generateControls();
showPage(mCurrentPageNum, true, this.activity);
}
}
When the user swipe on the page, I navigate to next page or previous page. For that I am calling the following function written in fragment from Mainactivity.
public void Readpage(int index, boolean PdfReload, Activity activity)
{
//context=activity;
//pageLayout = (RelativeLayout) rootView.findViewById(R.id.pagelayout);
//mImageView = (ImageView) rootView.findViewById(R.id.pdfImage);
showPage(index, true, activity);
pageControlsList = pdfRenderer.GetPageControls();
if (pageControlsList != null) {
generateControls();
}
}
Generatecontrols method is called if there are any controls in the page and generated dynamically. The code is as follows (given only one control for sample).
public void generateControls() {
//iterate loop to create each control
for (Map.Entry<Integer, PageElement> ctrl : pageControlsList.entrySet()) {
Integer ctrlKey = ctrl.getKey();
PageElement pageField = ctrl.getValue();
String name = pageField.getName();
int type = pageField.getType();
int pdfw = (int) pdfRenderer.getPage_width();
int pdfh = (int) pdfRenderer.getPage_height();
//get dimensions of the control
int left = (int) pageField.getLeft();
int top = (int) pageField.getTop();
int right = (int) pageField.getRight();
int bottom = (int) pageField.getBottom();
int width = (int) pageField.getWidth();
int height = (int) pageField.getHeight();
//calculate dimensions w.r.t. screen size
int ctrlW = scrwidth * width / pdfw;
int ctrlH = scrheight * height / pdfh;
int ctrlLeft = (int) (scrwidth * left) / pdfw;
int ctrlTop = (int) (((scrheight * (pdfh - top)) / pdfh));
int ctrlRight = (int) (scrwidth * right) / pdfw;
int ctrlBottom = (int) (scrheight * bottom / pdfh);
//set dimensions of the control with layout parameters
RelativeLayout.LayoutParams ctrllp = new RelativeLayout.LayoutParams(ctrlW, ctrlH);
ctrllp.setMargins(ctrlLeft, ctrlTop, 0, 0);
//generate controls based on the type of control
if (type == 2) { //checkbox
CheckBox myChkBox = new CheckBox(context);
myChkBox.setId(ctrlKey);
myChkBox.setFocusable(false);
myChkBox.setEnabled(false);
if (pageField.ExportValue().contains("Off"))
myChkBox.setChecked(false);
else
myChkBox.setChecked(true);
pageLayout.setLayoutParams(ctrllp);
pageLayout.addView(myChkBox, ctrllp);
}
It works fine even if the first page contains any controls or not. Once I swipe if any other page contains controls then i can see only a blank fragment. If no controls then I can see everything working perfectly. I tried many ways but none worked for me. Any help please.

After some R& D I found the problem in my code. Simply write the code in the main activity instead of Fragment. Render the controls in the activity but not in fragment.
//to display page controls during appload
pageControlsList = pdfRenderer.GetPageControls();
if (pageControlsList != null) {
if (pageControlsList.size() > 0) {
generateControls();
//fillDefaultDocControls();
mfrg.showPage(pdfRenderer.getmCurrentPageNum(), true, this);
}
}
simply generate controls and call the fragment to show the page.

Related

invalidate not redrawing view on api 25

I have a custom view that extends LinearLayout.
The view looks like progress bar with a little icon that moves on every click.
the updating method is :
public void setPointerOffset(int mPointerOffset) {
this.mPointerOffset = mPointerOffset;
updateSlider();
invalidate();
requestLayout();
}
private void updateSlider() {
PercentFrameLayout.LayoutParams params = (PercentFrameLayout.LayoutParams) mPointer.getLayoutParams();
PercentLayoutHelper.PercentLayoutInfo info = params.getPercentLayoutInfo();
if (mPointerOffset < MIN_OFFSET)
mPointerOffset = MIN_OFFSET;
if (mPointerOffset > MAX_OFFSET)
mPointerOffset = MAX_OFFSET;
float percent = mPointerOffset * 0.01f;
info.startMarginPercent = percent;
}
This method is fired up from onClickListener.
This is working great in low api like 17, but on the lest on (25) it doesn't working at all.
setting layout params to "mPointer" semms to fix it.
private void updateSlider() {
PercentFrameLayout.LayoutParams params = (PercentFrameLayout.LayoutParams) mPointer.getLayoutParams();
PercentLayoutHelper.PercentLayoutInfo info = params.getPercentLayoutInfo();
if (mPointerOffset < MIN_OFFSET)
mPointerOffset = MIN_OFFSET;
if (mPointerOffset > MAX_OFFSET)
mPointerOffset = MAX_OFFSET;
float percent = mPointerOffset * 0.01f;
info.startMarginPercent = percent;
mPointer.setLayoutParams(params);
}

How to animate ImageView from center-crop to fill the screen and vice versa (facebook style)?

Background
Facebook app has a nice transition animation between a small image on a post, and an enlarged mode of it that the user can also zoom to it.
As I see it, the animation not only enlarges and moves the imageView according to its previous location and size, but also reveals content instead of stretching the content of the imageView.
This can be seen using the next sketch i've made:
The question
How did they do it? did they really have 2 views animating to reveal the content?
How did they make it so fluid as if it's a single view?
the only tutorial i've seen (link here) of an image that is enlarged to full screen doesn't show well when the thumbnail is set to be center-crop.
Not only that, but it works even on low API of Android.
does anybody know of a library that has a similar ability?
EDIT: I've found a way and posted an answer, but it's based on changing the layoutParams , and i think it's not efficient and recommended.
I've tried using the normal animations and other animation tricks, but for now that's the only thing that worked for me.
If anyone know what to do in order to make it work in a better way, please write it down.
Ok, i've found a possible way to do it.
i've made the layoutParams as variables that keep changing using the ObjectAnimator of the nineOldAndroids library. i think it's not the best way to achieve it since it causes a lot of onDraw and onLayout, but if the container has only a few views and doesn't change its size, maybe it's ok.
the assumption is that the imageView that i animate will take the exact needed size in the end, and that (currently) both the thumbnail and the animated imageView have the same container (but it should be easy to change it.
as i've tested, it is also possible to add zoom features by extending the TouchImageView class . you just set the scale type in the beginning to center-crop, and when the animation ends you set it back to matrix, and if you want, you can set the layoutParams to fill the entire container (and set the margin to 0,0).
i also wonder how come the AnimatorSet didn't work for me, so i will show here something that works, hoping someone could tell me what i should do.
here's the code:
MainActivity.java
public class MainActivity extends Activity {
private static final int IMAGE_RES_ID = R.drawable.test_image_res_id;
private static final int ANIM_DURATION = 5000;
private final Handler mHandler = new Handler();
private ImageView mThumbnailImageView;
private CustomImageView mFullImageView;
private Point mFitSizeBitmap;
#Override
protected void onCreate(final Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mFullImageView = (CustomImageView) findViewById(R.id.fullImageView);
mThumbnailImageView = (ImageView) findViewById(R.id.thumbnailImageView);
mHandler.postDelayed(new Runnable() {
#Override
public void run() {
prepareAndStartAnimation();
}
}, 2000);
}
private void prepareAndStartAnimation() {
final int thumbX = mThumbnailImageView.getLeft(), thumbY = mThumbnailImageView.getTop();
final int thumbWidth = mThumbnailImageView.getWidth(), thumbHeight = mThumbnailImageView.getHeight();
final View container = (View) mFullImageView.getParent();
final int containerWidth = container.getWidth(), containerHeight = container.getHeight();
final Options bitmapOptions = getBitmapOptions(getResources(), IMAGE_RES_ID);
mFitSizeBitmap = getFitSize(bitmapOptions.outWidth, bitmapOptions.outHeight, containerWidth, containerHeight);
mThumbnailImageView.setVisibility(View.GONE);
mFullImageView.setVisibility(View.VISIBLE);
mFullImageView.setContentWidth(thumbWidth);
mFullImageView.setContentHeight(thumbHeight);
mFullImageView.setContentX(thumbX);
mFullImageView.setContentY(thumbY);
runEnterAnimation(containerWidth, containerHeight);
}
private Point getFitSize(final int width, final int height, final int containerWidth, final int containerHeight) {
int resultHeight, resultWidth;
resultHeight = height * containerWidth / width;
if (resultHeight <= containerHeight) {
resultWidth = containerWidth;
} else {
resultWidth = width * containerHeight / height;
resultHeight = containerHeight;
}
return new Point(resultWidth, resultHeight);
}
public void runEnterAnimation(final int containerWidth, final int containerHeight) {
final ObjectAnimator widthAnim = ObjectAnimator.ofInt(mFullImageView, "contentWidth", mFitSizeBitmap.x)
.setDuration(ANIM_DURATION);
final ObjectAnimator heightAnim = ObjectAnimator.ofInt(mFullImageView, "contentHeight", mFitSizeBitmap.y)
.setDuration(ANIM_DURATION);
final ObjectAnimator xAnim = ObjectAnimator.ofInt(mFullImageView, "contentX",
(containerWidth - mFitSizeBitmap.x) / 2).setDuration(ANIM_DURATION);
final ObjectAnimator yAnim = ObjectAnimator.ofInt(mFullImageView, "contentY",
(containerHeight - mFitSizeBitmap.y) / 2).setDuration(ANIM_DURATION);
widthAnim.start();
heightAnim.start();
xAnim.start();
yAnim.start();
// TODO check why using AnimatorSet doesn't work here:
// final com.nineoldandroids.animation.AnimatorSet set = new AnimatorSet();
// set.playTogether(widthAnim, heightAnim, xAnim, yAnim);
}
public static BitmapFactory.Options getBitmapOptions(final Resources res, final int resId) {
final BitmapFactory.Options bitmapOptions = new BitmapFactory.Options();
bitmapOptions.inJustDecodeBounds = true;
BitmapFactory.decodeResource(res, resId, bitmapOptions);
return bitmapOptions;
}
}
activity_main.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity" >
<com.example.facebookstylepictureanimationtest.CustomImageView
android:id="#+id/fullImageView"
android:layout_width="0px"
android:layout_height="0px"
android:background="#33ff0000"
android:scaleType="centerCrop"
android:src="#drawable/test_image_res_id"
android:visibility="invisible" />
<ImageView
android:id="#+id/thumbnailImageView"
android:layout_width="100dp"
android:layout_height="100dp"
android:layout_alignParentBottom="true"
android:layout_alignParentRight="true"
android:scaleType="centerCrop"
android:src="#drawable/test_image_res_id" />
</RelativeLayout>
CustomImageView.java
public class CustomImageView extends ImageView {
public CustomImageView(final Context context) {
super(context);
}
public CustomImageView(final Context context, final AttributeSet attrs) {
super(context, attrs);
}
public CustomImageView(final Context context, final AttributeSet attrs, final int defStyle) {
super(context, attrs, defStyle);
}
public void setContentHeight(final int contentHeight) {
final LayoutParams layoutParams = getLayoutParams();
layoutParams.height = contentHeight;
setLayoutParams(layoutParams);
}
public void setContentWidth(final int contentWidth) {
final LayoutParams layoutParams = getLayoutParams();
layoutParams.width = contentWidth;
setLayoutParams(layoutParams);
}
public int getContentHeight() {
return getLayoutParams().height;
}
public int getContentWidth() {
return getLayoutParams().width;
}
public int getContentX() {
return ((MarginLayoutParams) getLayoutParams()).leftMargin;
}
public void setContentX(final int contentX) {
final MarginLayoutParams layoutParams = (MarginLayoutParams) getLayoutParams();
layoutParams.leftMargin = contentX;
setLayoutParams(layoutParams);
}
public int getContentY() {
return ((MarginLayoutParams) getLayoutParams()).topMargin;
}
public void setContentY(final int contentY) {
final MarginLayoutParams layoutParams = (MarginLayoutParams) getLayoutParams();
layoutParams.topMargin = contentY;
setLayoutParams(layoutParams);
}
}
Another solution, if you just want to make an animation of an image from small to large, you can try ActivityOptions.makeThumbnailScaleUpAnimation or makeScaleUpAnimationand see if they suit you.
http://developer.android.com/reference/android/app/ActivityOptions.html#makeThumbnailScaleUpAnimation(android.view.View, android.graphics.Bitmap, int, int)
You can achieve this through Transition Apiļ¼Œ and this the resut gif:
essential code below:
private void zoomIn() {
ViewGroup.LayoutParams layoutParams = mImage.getLayoutParams();
int width = layoutParams.width;
int height = layoutParams.height;
layoutParams.width = (int) (width * 2);
layoutParams.height = height * 2;
mImage.setLayoutParams(layoutParams);
mImage.setScaleType(ImageView.ScaleType.FIT_CENTER);
TransitionSet transitionSet = new TransitionSet();
Transition bound = new ChangeBounds();
transitionSet.addTransition(bound);
Transition changeImageTransform = new ChangeImageTransform();
transitionSet.addTransition(changeImageTransform);
transitionSet.setDuration(1000);
TransitionManager.beginDelayedTransition(mRootView, transitionSet);
}
View demo on github
sdk version >= 21
I found a way to get a similar affect in a quick prototype. It might not be suitable for production use (I'm still investigating), but it is quick and easy.
Use a fade transition on your activity/fragment transition (which starts with the ImageView in exactly the same position). The fragment version:
final FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);
...etc
The activity version:
Intent intent = new Intent(context, MyDetailActivity.class);
startActivity(intent);
getActivity().overridePendingTransition(android.R.anim.fade_in, android.R.anim.fade_out);
This gives a smooth transition without a flicker.
Adjust the layouts dynamically in the onStart() of the new fragment (you need to save member fields to the appropriate parts of your UI in onCreateView, and add some flags to ensure this code only gets called once).
#Override
public void onStart() {
super.onStart();
// Remove the padding on any layouts that the image view is inside
mMainLayout.setPadding(0, 0, 0, 0);
// Get the screen size using a utility method, e.g.
// http://stackoverflow.com/a/12082061/112705
// then work out your desired height, e.g. using the image aspect ratio.
int desiredHeight = (int) (screenWidth * imgAspectRatio);
// Resize the image to fill the whole screen width, removing
// any layout margins that it might have (you may need to remove
// padding too)
LinearLayout.LayoutParams layoutParams =
new LinearLayout.LayoutParams(screenWidth, desiredHeight);
layoutParams.setMargins(0, 0, 0, 0);
mImageView.setLayoutParams(layoutParams);
}
I think the easiest way is to animate the height of the ImageView (a regular imageview, not necessary a custom view) while keeping the scaleType to centerCrop until full height, which you can know in advance if you set the image height to wrap_content in your layout and then use a ViewTreeObserver to know when the layout has ended, so you can get the ImageView height and then set the new "collapsed" height. I have not tested it but this is how I would do it.
You can also have a look at this post, they do something similar http://nerds.airbnb.com/host-experience-android/
I'm not sure why everyone is talking about the framework. Using other peoples code can be great at times; but it sounds like what you are after is precise control over the look. By getting access to the graphics context you can have that. The task is pretty simple in any environment that has a graphics context. In android you can get it by overriding the onDraw method and using the Canvas Object. It has everything you need to draw an image at many different scales, positions and clippings. You can even use a matrix if your familiar with that type of thing.
Steps
Make sure you have exact control of positioning, scale, and clip. This means disabling any layouts or auto-alignment that might be setup inside your objects container.
Figure you out what your parameter t will be for linear interpolation and how you will want it to relate to time. How fast or slow, and will there be any easing. t should be dependent on time.
After the thumbnails are cached, load the full scale image in the background. But don't show it yet.
When the animation trigger fires, show the large image and drive your animation with your t parameter using interpolation between the initial properties' states to the final properties' states. Do this for all three properties, position, scale and clip. So for all properties do the following:
Sinterpolated = Sinitial * (t-1) + Sfinal * t;
// where
// t is between 0.0 and 1.0
// and S is the states value
// for every part of scale, position, and clip
//
// Sinitial is what you are going from
// Sfinal is what you are going to
//
// t should change from 0.0->1.0 in
// over time anywhere from 12/sec or 60/sec.
If all your properties are driven by the same parameter the animation will be smooth. As an added bonus, here is a tip for timing. As long as you can keep your t parameter between 0 and 1, easing in or out can be hacked with one line of code:
// After your t is all setup
t = t * t; // for easing in
// or
t = Math.sqrt(t); // for easing out
I made a sample code in Github.
The key of this code is using canvas.clipRect().
But, it only works when the CroppedImageview is match_parent.
To explain simply,
I leave scale and translation animation to ViewPropertyAnimator.
Then, I can focus on cropping the image.
Like above picture, calculate the clipping region, and change the clip region to final view size.
AnimationController
class ZoomAnimationController(private val view: CroppedImageView, startRect: Rect, private val viewRect: Rect, imageSize: Size) {
companion object {
const val DURATION = 300L
}
private val startViewRect: RectF
private val scale: Float
private val startClipRect: RectF
private val animatingRect: Rect
private var cropAnimation: ValueAnimator? = null
init {
val startImageRect = getProportionalRect(startRect, imageSize, ImageView.ScaleType.CENTER_CROP)
startViewRect = getProportionalRect(startImageRect, viewRect.getSize(), ImageView.ScaleType.CENTER_CROP)
scale = startViewRect.width() / viewRect.width()
val finalImageRect = getProportionalRect(viewRect, imageSize, ImageView.ScaleType.FIT_CENTER)
startClipRect = getProportionalRect(finalImageRect, startRect.getSize() / scale, ImageView.ScaleType.FIT_CENTER)
animatingRect = Rect()
startClipRect.round(animatingRect)
}
fun init() {
view.x = startViewRect.left
view.y = startViewRect.top
view.pivotX = 0f
view.pivotY = 0f
view.scaleX = scale
view.scaleY = scale
view.setClipRegion(animatingRect)
}
fun startAnimation() {
cropAnimation = createCropAnimator().apply {
start()
}
view.animate()
.x(0f)
.y(0f)
.scaleX(1f)
.scaleY(1f)
.setDuration(DURATION)
.start()
}
private fun createCropAnimator(): ValueAnimator {
return ValueAnimator.ofFloat(0f, 1f).apply {
duration = DURATION
addUpdateListener {
val weight = animatedValue as Float
animatingRect.set(
(startClipRect.left * (1 - weight) + viewRect.left * weight).toInt(),
(startClipRect.top * (1 - weight) + viewRect.top * weight).toInt(),
(startClipRect.right * (1 - weight) + viewRect.right * weight).toInt(),
(startClipRect.bottom * (1 - weight) + viewRect.bottom * weight).toInt()
)
Log.d("SSO", "animatingRect=$animatingRect")
view.setClipRegion(animatingRect)
}
}
}
private fun getProportionalRect(viewRect: Rect, imageSize: Size, scaleType: ImageView.ScaleType): RectF {
return getProportionalRect(RectF(viewRect), imageSize, scaleType)
}
private fun getProportionalRect(viewRect: RectF, imageSize: Size, scaleType: ImageView.ScaleType): RectF {
val viewRatio = viewRect.height() / viewRect.width()
if ((scaleType == ImageView.ScaleType.FIT_CENTER && viewRatio > imageSize.ratio)
|| (scaleType == ImageView.ScaleType.CENTER_CROP && viewRatio <= imageSize.ratio)) {
val width = viewRect.width()
val height = width * imageSize.ratio
val paddingY = (height - viewRect.height()) / 2f
return RectF(viewRect.left, viewRect.top - paddingY, viewRect.right, viewRect.bottom + paddingY)
} else if ((scaleType == ImageView.ScaleType.FIT_CENTER && viewRatio <= imageSize.ratio)
|| (scaleType == ImageView.ScaleType.CENTER_CROP && viewRatio > imageSize.ratio)){
val height = viewRect.height()
val width = height / imageSize.ratio
val paddingX = (width - viewRect.width()) / 2f
return RectF(viewRect.left - paddingX, viewRect.top, viewRect.right + paddingX, viewRect.bottom)
}
return RectF()
}
CroppedImageView
override fun onDraw(canvas: Canvas?) {
if (clipRect.width() > 0 && clipRect.height() > 0) {
canvas?.clipRect(clipRect)
}
super.onDraw(canvas)
}
fun setClipRegion(rect: Rect) {
clipRect.set(rect)
invalidate()
}
it only works when the CroppedImageview is match_parent,
because
The paths from start to end is included in CroppedImageView. If not, animation is not shown. So, Making it's size match_parent is easy to think.
I didn't implement the code for special case...

How to prevent URLs from being wrapped in TextView?

I have a multiline TextView which can display some optional URL. Now I have a problem: some of my long URLs displayed wrapped in the position of ://
sometext sometext http:// <-- AUTO LINE WRAP
google.com/
How can I disable wrapping for the whole URL or at least for http(s):// prefix? I still need text wrapping to be enabled however.
My text should wrap like that
sometext sometext <-- AUTO LINE WRAP
http://google.com/
This is just proof of concept to implement custom wrap for textview.
You may need to add/edit conditions according to your requirement.
If your requirement is that our textview class must show multiline in such a way that it should not end with certain text ever (here http:// and http:),
I have modified the code of very popular textview class over SO to meet this requirement:
Source :
Auto Scale TextView Text to Fit within Bounds
Changes:
private boolean mCustomLineWrap = true;
/**
* Resize the text size with specified width and height
* #param width
* #param height
*/
public void resizeText(int width, int height) {
CharSequence text = getText();
// Do not resize if the view does not have dimensions or there is no text
if(text == null || text.length() == 0 || height <= 0 || width <= 0 || mTextSize == 0) {
return;
}
// Get the text view's paint object
TextPaint textPaint = getPaint();
// Store the current text size
float oldTextSize = textPaint.getTextSize();
// If there is a max text size set, use the lesser of that and the default text size
float targetTextSize = mMaxTextSize > 0 ? Math.min(mTextSize, mMaxTextSize) : mTextSize;
// Get the required text height
int textHeight = getTextHeight(text, textPaint, width, targetTextSize);
// Until we either fit within our text view or we had reached our min text size, incrementally try smaller sizes
while(textHeight > height && targetTextSize > mMinTextSize) {
targetTextSize = Math.max(targetTextSize - 2, mMinTextSize);
textHeight = getTextHeight(text, textPaint, width, targetTextSize);
}
if(mCustomLineWrap ) {
// Draw using a static layout
StaticLayout layout = new StaticLayout(text, textPaint, width, Alignment.ALIGN_NORMAL, mSpacingMult, mSpacingAdd, false);
// Check that we have a least one line of rendered text
if(layout.getLineCount() > 0) {
String lineText[] = new String[layout.getLineCount()];
// Since the line at the specific vertical position would be cut off,
// we must trim up to the previous line
String wrapStr = "http:", wrapStrWithSlash = "http://";
boolean preAppendWrapStr = false, preAppendWrapStrWithSlash = false ;
for(int lastLine = 0; lastLine < layout.getLineCount(); lastLine++)
{
int start = layout.getLineStart(lastLine);
int end = layout.getLineEnd(lastLine);
lineText[lastLine] = ((String) getText()).substring(start,end);
if(preAppendWrapStr)
{
lineText[lastLine] = "\n" + wrapStr + lineText[lastLine];
preAppendWrapStr = false;
}
else if(preAppendWrapStrWithSlash)
{
lineText[lastLine] = "\n" + wrapStrWithSlash + lineText[lastLine];
preAppendWrapStrWithSlash = false;
}
if(lineText[lastLine].endsWith(wrapStr))
{
preAppendWrapStr = true;
lineText[lastLine] = lineText[lastLine].substring(0,lineText[lastLine].lastIndexOf(wrapStr));
}
if( lineText[lastLine].endsWith(wrapStrWithSlash))
{
preAppendWrapStrWithSlash = true;
lineText[lastLine] = lineText[lastLine].substring(0,lineText[lastLine].lastIndexOf(wrapStrWithSlash));
}
}
String compString = "";
for(String lineStr : lineText)
{
compString += lineStr;
}
setText(compString);
}
}
// Some devices try to auto adjust line spacing, so force default line spacing
// and invalidate the layout as a side effect
textPaint.setTextSize(targetTextSize);
setLineSpacing(mSpacingAdd, mSpacingMult);
// Notify the listener if registered
if(mTextResizeListener != null) {
mTextResizeListener.onTextResize(this, oldTextSize, targetTextSize);
}
// Reset force resize flag
mNeedsResize = false;
}

Implementing a multicolumn ListView with independent Row-heights

I would like to create a list of about 200 ImageViews (random heights) with the following layout in a 'collage' fashion:
Normally I would do this in a ListView for the peformance gained by using Adapters but since i want the images to be displayed in columns, and with different height (See picture Example ) depending on the pictures, I cannot use a single listview for this purpose.
I have tried implementing this layout with:
Three ListViews with synchronized scrolling = Slow
Single ListView with each row containing three images = Not allowing different heights
GridView = Not allowing different heights
GridLayout = Difficult to implement different heights programmatically. Because of no adapter, OutOfMemoryErrors are common
FlowLayout = Because of no adapter, OutOfMemoryErrors are common
ScrollView with three Vertical LinearLayouts = Best solution so far, but OutOfMemoryErrors are common
I have ended up using three LinearLayouts in a ScrollView, but this is far from optimal. I would rather use something with an Adapter.
EDIT
I have been looking at the StaggeredGridView, as in a response below, but I find it quite buggy. Are there any implementations of this that are more stable?
I think I have a working solution for you.
The main files mentioned here are also on PasteBin at http://pastebin.com/u/morganbelford
I basically implemented a simplified equivalent of the github project mentioned, https://github.com/maurycyw/StaggeredGridView, using a set of excellent LoopJ SmartImageViews.
My solution is not nearly as generic and flexible as the StaggeredGridView, but seems to work well, and quickly. One big difference functionally is that we layout the images always just left to right, then left to right again. We don't try to put the next image in the shortest column. This makes the bottom of the view a little more uneven, but generates less shifting around during initial load from the web.
There are three main classes, a custom StagScrollView, which contains a custom StagLayout (subclassed FrameLayout), which manages a set of ImageInfo data objects.
Here is our layout, stag_layout.xml (the 1000dp initial height is irrelevant, since it will get recomputed in code based on the image sizes):
// stag_layout.xml
<?xml version="1.0" encoding="utf-8"?>
<com.morganbelford.stackoverflowtest.pinterest.StagScrollView xmlns:a="http://schemas.android.com/apk/res/android"
a:id="#+id/scroller"
a:layout_width="match_parent"
a:layout_height="match_parent" >
<com.morganbelford.stackoverflowtest.pinterest.StagLayout
a:id="#+id/frame"
a:layout_width="match_parent"
a:layout_height="1000dp"
a:background="#drawable/pinterest_bg" >
</com.morganbelford.stackoverflowtest.pinterest.StagLayout>
</com.morganbelford.stackoverflowtest.pinterest.StagScrollView>
Here is our main Activity's onCreate, which uses the layout. The StagActivity just basically tells the StagLayout what urls to use, what the margin should be between each image, and how many columns there are. For more modularity, we could have passed these params to the StagScrollView (which contains the StagLayout, but the the scroll view would have just had to pass them down the layout anyway):
// StagActivity.onCreate
setContentView(R.layout.stag_layout);
StagLayout container = (StagLayout) findViewById(R.id.frame);
DisplayMetrics metrics = new DisplayMetrics();
((WindowManager)getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay().getMetrics(metrics);
float fScale = metrics.density;
String[] testUrls = new String[] {
"http://www.westlord.com/wp-content/uploads/2010/10/French-Bulldog-Puppy-242x300.jpg",
"http://upload.wikimedia.org/wikipedia/en/b/b0/Cream_french_bulldog.jpg",
"http://bulldogbreeds.com/breeders/pics/french_bulldog_64368.jpg",
"http://www.drsfostersmith.com/images/articles/a-french-bulldog.jpg",
"http://2.bp.blogspot.com/-ui2p5Z_DJIs/Tgdo09JKDbI/AAAAAAAAAQ8/aoTdw2m_bSc/s1600/Lilly+%25281%2529.jpg",
"http://www.dogbreedinfo.com/images14/FrenchBulldog7.jpg",
"http://dogsbreed.net/wp-content/uploads/2011/03/french-bulldog.jpg",
"http://www.theflowerexpert.com/media/images/giftflowers/flowersandoccassions/valentinesdayflowers/sea-of-flowers.jpg.pagespeed.ce.BN9Gn4lM_r.jpg",
"http://img4-2.sunset.timeinc.net/i/2008/12/image-adds-1217/alcatraz-flowers-galliardia-m.jpg?300:300",
"http://images6.fanpop.com/image/photos/32600000/bt-jpgcarnation-jpgFlower-jpgred-rose-flow-flowers-32600653-1536-1020.jpg",
"http://the-bistro.dk/wp-content/uploads/2011/07/Bird-of-Paradise.jpg",
"http://2.bp.blogspot.com/_SG-mtHOcpiQ/TNwNO1DBCcI/AAAAAAAAALw/7Hrg5FogwfU/s1600/birds-of-paradise.jpg",
"http://wac.450f.edgecastcdn.net/80450F/screencrush.com/files/2013/01/get-back-to-portlandia-tout.jpg",
"http://3.bp.blogspot.com/-bVeFyAAgBVQ/T80r3BSAVZI/AAAAAAAABmc/JYy8Hxgl8_Q/s1600/portlandia.jpg",
"http://media.oregonlive.com/ent_impact_tvfilm/photo/portlandia-season2jpg-7d0c21a9cb904f54.jpg",
"https://twimg0-a.akamaihd.net/profile_images/1776615163/PortlandiaTV_04.jpg",
"http://getvideoartwork.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=85796&g2_serialNumber=1",
"http://static.tvtome.com/images/genie_images/story/2011_usa/p/portlandia_foodcarts.jpg",
"http://imgc.classistatic.com/cps/poc/130104/376r1/8728dl1_27.jpeg",
};
container.setUrls(testUrls, fScale * 10, 3); // pass in pixels for margin, rather than dips
Before we get to the meat of the solution, here is our simple StagScrollView subclass. His only special behavior is to tell his main child (our StagLayout) which the currently visible area is, so that he can efficiently use the smallest possible number of realized subviews.
// StagScrollView
StagLayout _frame;
#Override
protected void onFinishInflate() {
super.onFinishInflate();
_frame = (StagLayout) findViewById(R.id.frame);
}
#Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
if (oldh == 0)
_frame.setVisibleArea(0, h);
}
#Override
protected void onScrollChanged(int l, int t, int oldl, int oldt) {
super.onScrollChanged(l, t, oldl, oldt);
_frame.setVisibleArea(t, t + getHeight());
}
Here then is the most important class StagLayout.
First, setUrls sets up our data structures.
public void setUrls(String[] urls, float pxMargin, int cCols)
{
_pxMargin = pxMargin;
_cCols = cCols;
_cMaxCachedViews = 2 * cCols;
_infos = new ArrayList<ImageInfo>(urls.length); // should be urls.length
for (int i = 0; i < 200; i++) // should be urls.length IRL, but this is a quick way to get more images, by using repeats
{
final String sUrl = urls[i % urls.length]; // could just be urls[i] IRL
_infos.add(new ImageInfo(sUrl, new OnClickListener() {
#Override
public void onClick(View v) {
Log.d("StagLayout", String.format("Image clicked: url == %s", sUrl));
}
}));
}
_activeInfos = new HashSet<ImageInfo>(_infos.size());
_cachedViews = new ArrayList<SmartImageView>(_cMaxCachedViews);
requestLayout(); // perform initial layout
}
Our main data structure is ImageInfo. It is a kind of lightweight placeholder that allows us to keep track of where each image is going to be displayed, when it needs to be. When we layout our child views, we will use the information in the ImageInfo to figure out where to put the actual view. A good way to think about ImageInfo is as a "virtual image view".
See comments inline for details.
public class ImageInfo {
private String _sUrl;
// these rects are in float dips
private RectF _rLoaded; // real size of the corresponding loaded SmartImageView
private RectF _rDefault; // lame default rect in case we don't have anything better to go on
private RectF _rLayout; // rect that our parent tells us to use -- this corresponds to a real View's layout rect as specified when parent ViewGroup calls child.layout(l,t,r,b)
private SmartImageView _vw;
private View.OnClickListener _clickListener;
public ImageInfo(String sUrl, View.OnClickListener clickListener) {
_rDefault = new RectF(0, 0, 100, 100);
_sUrl = sUrl;
_rLayout = new RectF();
_clickListener = clickListener;
}
// Bounds will be called by the StagLayout when it is laying out views.
// We want to return the most accurate bounds we can.
public RectF bounds() {
// if there is not yet a 'real' bounds (from a loaded SmartImageView), try to get one
if (_rLoaded == null && _vw != null) {
int h = _vw.getMeasuredHeight();
int w = _vw.getMeasuredWidth();
// if the SmartImageView thinks it knows how big it wants to be, then ok
if (h > 0 && w > 0) {
_rLoaded = new RectF(0, 0, w, h);
}
}
if (_rLoaded != null)
return _rLoaded;
// if we have not yet gotten a real bounds from the SmartImageView, just use this lame rect
return _rDefault;
}
// Reuse our layout rect -- this gets called a lot
public void setLayoutBounds(float left, float top, float right, float bottom) {
_rLayout.top = top;
_rLayout.left = left;
_rLayout.right = right;
_rLayout.bottom = bottom;
}
public RectF layoutBounds() {
return _rLayout;
}
public SmartImageView view() {
return _vw;
}
// This is called during layout to attach or detach a real view
public void setView(SmartImageView vw)
{
if (vw == null && _vw != null)
{
// if detaching, tell view it has no url, or handlers -- this prepares it for reuse or disposal
_vw.setImage(null, (SmartImageTask.OnCompleteListener)null);
_vw.setOnClickListener(null);
}
_vw = vw;
if (_vw != null)
{
// We are attaching a view (new or re-used), so tell it its url and attach handlers.
// We need to set this OnCompleteListener so we know when to ask the SmartImageView how big it really is
_vw.setImageUrl(_sUrl, R.drawable.default_image, new SmartImageTask.OnCompleteListener() {
final private View vw = _vw;
#Override
public void onComplete() {
vw.measure(MeasureSpec.makeMeasureSpec(LayoutParams.WRAP_CONTENT, MeasureSpec.UNSPECIFIED), MeasureSpec.makeMeasureSpec(LayoutParams.WRAP_CONTENT, MeasureSpec.UNSPECIFIED));
int h = vw.getMeasuredHeight();
int w = vw.getMeasuredWidth();
_rLoaded = new RectF(0, 0, w, h);
Log.d("ImageInfo", String.format("Settings loaded size onComplete %d x %d for %s", w, h, _sUrl));
}
});
_vw.setOnClickListener(_clickListener);
}
}
// Simple way to answer the question, "based on where I have laid you out, are you visible"
public boolean overlaps(float top, float bottom) {
if (_rLayout.bottom < top)
return false;
if (_rLayout.top > bottom)
return false;
return true;
}
}
The rest of the magic happens in StagLayout's onMeasure and onLayout.
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int width = MeasureSpec.getSize(widthMeasureSpec);
// Measure each real view that is currently realized. Initially there are none of these
for (ImageInfo info : _activeInfos)
{
View v = info.view();
v.measure(MeasureSpec.makeMeasureSpec(LayoutParams.WRAP_CONTENT, MeasureSpec.UNSPECIFIED), MeasureSpec.makeMeasureSpec(LayoutParams.WRAP_CONTENT, MeasureSpec.UNSPECIFIED));
}
// This arranges all of the imageinfos every time, and sets _maxBottom
//
computeImageInfo(width);
setMeasuredDimension(width, (int)_maxBottom);
}
#Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
// This figures out what real SmartImageViews we need, creates new ones, re-uses old ones, etc.
// After this call _activeInfos is correct -- the list of ImageInfos that are currently attached to real SmartImageViews
setupSubviews();
for (ImageInfo info : _activeInfos)
{
// Note: The layoutBounds of each info is actually computed in onMeasure
RectF rBounds = info.layoutBounds();
// Tell the real view where it should be
info.view().layout((int)rBounds.left, (int)rBounds.top, (int)rBounds.right, (int)rBounds.bottom);
}
}
Ok, now let's see how we actually arrange all the ImageInfos.
private void computeImageInfo(float width)
{
float dxMargin = _pxMargin;
float dyMargin = _pxMargin;
float left = 0;
float tops[] = new float[_cCols]; // start at 0
float widthCol = (int)((width - (_cCols + 1) * dxMargin) / _cCols);
_maxBottom = 0;
// layout the images -- set their layoutrect based on our current location and their bounds
for (int i = 0; i < _infos.size(); i++)
{
int iCol = i % _cCols;
// new row
if (iCol == 0)
{
left = dxMargin;
for (int j = 0; j < _cCols; j++)
tops[j] += dyMargin;
}
ImageInfo info = _infos.get(i);
RectF bounds = info.bounds();
float scale = widthCol / bounds.width(); // up or down, for now, it does not matter
float layoutHeight = bounds.height() * scale;
float top = tops[iCol];
float bottom = top + layoutHeight;
info.setLayoutBounds(left, top, left + widthCol, bottom);
if (bottom > _maxBottom)
_maxBottom = bottom;
left += widthCol + dxMargin;
tops[iCol] += layoutHeight;
}
// TODO Optimization: build indexes of tops and bottoms
// Exercise for reader
_maxBottom += dyMargin;
}
And, now let's see how we create, resuse and dispose of real SmartImageViews during onLayout.
private void setupSubviews()
{
// We need to compute new set of active views
// TODO Optimize enumeration using indexes of tops and bottoms
// NeededInfos will be set of currently visible ImageInfos
HashSet<ImageInfo> neededInfos = new HashSet<ImageInfo>(_infos.size());
// NewInfos will be subset that are not currently assigned real views
HashSet<ImageInfo> newInfos = new HashSet<ImageInfo>(_infos.size());
for (ImageInfo info : _infos)
{
if (info.overlaps(_viewportTop, _viewportBottom))
{
neededInfos.add(info);
if (info.view() == null)
newInfos.add(info);
}
}
// So now we have the active ones. Lets get any we need to deactivate.
// Start with a copy of the _activeInfos from last time
HashSet<ImageInfo> unneededInfos = new HashSet<ImageInfo>(_activeInfos);
// And remove all the ones we need now, leaving ones we don't need any more
unneededInfos.removeAll(neededInfos);
// Detach all the views from these guys, and possibly reuse them
ArrayList<SmartImageView> unneededViews = new ArrayList<SmartImageView>(unneededInfos.size());
for (ImageInfo info : unneededInfos)
{
SmartImageView vw = info.view();
unneededViews.add(vw);
info.setView(null); // at this point view is still a child of parent
}
// So now we try to reuse the views, and create new ones if needed
for (ImageInfo info : newInfos)
{
SmartImageView vw = null;
if (unneededViews.size() > 0)
{
vw = unneededViews.remove(0); // grab one of these -- these are still children and so dont need to be added to parent
}
else if (_cachedViews.size() > 0)
{
vw = _cachedViews.remove(0); // else grab a cached one and re-add to parent
addViewInLayout(vw, -1, new FrameLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));
}
else
{
vw = new SmartImageView(getContext()); // create a whole new one
FrameLayout.LayoutParams lp = new FrameLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
addViewInLayout(vw, -1, lp); // and add to parent
}
info.setView(vw); // info should also set its data
}
// At this point, detach any unneeded views and add to our cache, up to limit
for (SmartImageView vw : unneededViews)
{
// tell view to cancel
removeViewInLayout(vw); // always remove from parent
if (_cachedViews.size() < _cMaxCachedViews)
_cachedViews.add(vw);
}
// Record the active ones for next time around
_activeInfos = neededInfos;
}
Remember that _viewportTop and _viewportBottom are set every time the user scrolls.
// called on every scroll by parent StagScrollView
public void setVisibleArea(int top, int bottom) {
_viewportTop = top;
_viewportBottom = bottom;
//fixup views
if (getWidth() == 0) // if we have never been measured, dont do this - it will happen in first layout shortly
return;
requestLayout();
}
You can have a look at https://github.com/maurycyw/StaggeredGridView
I have not worked with it personally, but you could atleast steal some concepts.
Create a list view in a layout.
Create another layout with same background as that of list view background layout with three Image Views (next to each other ie to the right of each other) with their properties set to Wrap_Content horizontally and the whole Views properties in which image views are put to Wrap_Content.
Inflate the layout in the getview() method of listview adapter. In this you need to set 3 set of images in Image Views of the inflated Layout.
Hope this helps!
I guess it can be implemented with three independent list view, only thing which you have to do it to inflate layout for imageview and add it to listview.
use following as layout parameters during inflation.
Layout Width : match_parent
layout Height: wrap_content
you can assign layout weight as .3 for all the three list view with layout_width as 0dp and height as fill_parent.
hope this helps.
Can't you use your current solution wrapped in a custom list ?
in getView method for each row inflate your existing solution (checking converview ofcourse)
i.e. ScrollView with three Vertical LinearLayouts.
Do you know why the 3 List View solution was slow?
How many different sizes are in each column? I think that for the recycling of views to be efficient, you would want to create a view type for each size of image, and then make sure that you use getItemViewType, to be sure that you're recycling the correct type of view. Otherwise, you will not get much benefit from the recycling. You would want to be able to just reset the source for the image view.

Get current visible text in textview

I have a long passage in a TextView which is wrapped around by ScrollView. Is there any way to find the current visible text?
I can find the number of lines, line height in textview and also scrollx and scrolly from scrollview, but find the linkage to the current displayed text. Please help! Thanks.
It is simple to do this:
int start = textView.getLayout().getLineStart(0);
int end = textView.getLayout().getLineEnd(textView.getLineCount() - 1);
String displayed = textView.getText().toString().substring(start, end);
Here. Get the line number of the first displayed line. Then get the line number of the second displayed line. Then get the text and count the number of words.
private int getNumberOfWordsDisplayed() {
int start = textView.getLayout().getLineStart(getFirstLineIndex());
int end = textView.getLayout().getLineEnd(getLastLineIndex());
return textView.getText().toString().substring(start, end).split(" ").length;
}
/**
* Gets the first line that is visible on the screen.
*
* #return
*/
public int getFirstLineIndex() {
int scrollY = scrollView.getScrollY();
Layout layout = textView.getLayout();
if (layout != null) {
return layout.getLineForVertical(scrollY);
}
Log.d(TAG, "Layout is null: ");
return -1;
}
/**
* Gets the last visible line number on the screen.
* #return last line that is visible on the screen.
*/
public int getLastLineIndex() {
int height = scrollView.getHeight();
int scrollY = scrollView.getScrollY();
Layout layout = textView.getLayout();
if (layout != null) {
return layout.getLineForVertical(scrollY + height);
}
return -1;
}
Using textView.getLayout().getEllipsisStart(0) only works if android:singleLine="true"
Here is a solution that will work if android:maxLines is set:
public static String getVisibleText(TextView textView) {
// test that we have a textview and it has text
if (textView==null || TextUtils.isEmpty(textView.getText())) return null;
Layout l = textView.getLayout();
if (l!=null) {
// find the last visible position
int end = l.getLineEnd(textView.getMaxLines()-1);
// get only the text after that position
return textView.getText().toString().substring(0,end);
}
return null;
}
Remember: this works after the view is already loaded.
Usage:
textView.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
#Override
public void onGlobalLayout() {
textView.getViewTreeObserver().removeOnGlobalLayoutListener(this);
Log.i("test" ,"VisibleText="+getVisibleText(textView));
}
});
You claim that you know scrollY, the current number of pixels scrolled. You also know the height of the window you're considering in pixels, so call that scrollViewHeight. Then
int scrollY; // This is your current scroll position in pixels.
int scrollViewHeight; // This is the height of your scrolling window.
TextView textView; // This is the TextView we're considering.
String text = (String) textView.getText();
int charsPerLine = text.length() / textView.getLineCount();
int lineHeight = textView.getLineHeight();
int startLine = scrollY / lineHeight;
int endLine = startLine + scrollViewHeight/lineHeight + 1;
int startChar = charsPerLine * startLine;
int endChar = charsPerLine * (endLine+1) + 1;
String approxVisibleString = text.substring(startChar, endChar);
It's an approximation, so use it as a last resort.
I also having about the same problem myself. I needed first visible line from textview currently visible in recyclerview. If you are trying to get currently displayed first line of textview in recyclerview you may use the following code:
TextView tv = (TextView) recyclerView.getChildAt(0); //gets current visible child view
// this is for top visible
//view or the textview directly
Rect r1 = new Rect();
tv.getHitRect(r1);//gets visible rect of textview
Layout l = tv.getLayout();
int line = l.getLineForVertical(-1 * r1.top);//first visible line
int start = l.getLineStart(line);//visible line start
int end = l.getLineEnd(line);//visible line end
String displayed = tv.getText().toString().substring(start, end);
try use getEllipsisStart()
int end = textView.getLayout().getEllipsisStart(0);
This depends on the use of Ellipsize in the TextView. Try this:
public String getVisibleText(TextView tv) {
int lastLine = tv.getMaxLines() < 1 || tv.getMaxLines() > tv.getLineCount() ? tv.getLineCount() : tv.getMaxLines();
if (tv.getEllipsize() != null && tv.getEllipsize().equals(TextUtils.TruncateAt.END)) {
int ellCount = tv.getLayout().getEllipsisCount(lastLine - 1);
if (ellCount > 0 && tv.length() > ellCount)
return tv.getText().toString().substring(0, tv_title.getText().length() - ellCount);
return tv.getText().toString();
} else {
int end = tv.getLayout().getLineEnd(lastLine - 1);
return tv.getText().toString().substring(0, end);
}
}
...
textView.post(new Runnable() {
#Override
public void run() {
Log.d(TAG, getVisibleText(textView));
}
});
Assuming you have the scrolled line number, you can use the following to get displayed text:
int start = tv.getLayout().getLineStart(scrolllinenumber);
int end=scrolllinenumber+tv.getLayout().getHeight();
String displayedtext = tv.getText().toString().substring(start, end);

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