Develop Reference

Scale view to parent layout size

I am trying to scale a view to layout size by using object animator. The view is a LinearLayout. The view does stretch, but not till the screen size in both the directions (i.e X and Y).
Here is the code.
I feel that either the problem is with this:
The formula to calculate how much zoom must be done.
zoomTillX = screen_width/zoomView_width;
zoomTillY = screen_height/zoomView_height;
Or with the Animation property code that is done in a wrong way.
Please let me know how can I achieve a zoom in.
public class MainActivity extends AppCompatActivity {
TextView tv;
double screen_height;
LinearLayout zoomView;
double screen_width;
double zoomTillX;
double zoomTillY;
double zoomView_width;
double zoomView_height;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
tv = (TextView) findViewById(R.id.tv);
zoomView = (LinearLayout) findViewById(R.id.zoomView);
DisplayMetrics dm = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(dm);
screen_height = (double)dm.heightPixels;
screen_width = (double)dm.widthPixels;
zoomView.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
#Override
public void onGlobalLayout() {
zoomView.getViewTreeObserver().removeOnGlobalLayoutListener(this);
zoomView_width = (double)zoomView.getMeasuredWidth();
zoomView_height = (double)zoomView.getMeasuredHeight();
}
});
zoomView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
final Handler handler = new Handler(Looper.getMainLooper());
handler.postDelayed(new Runnable() {
#Override
public void run() {
if(zoomView_width > 0 && zoomView_height > 0)
{
zoomTillX = screen_width/zoomView_width;
zoomTillY = screen_height/zoomView_height;
Log.d("VIEW GET X IS ",String.valueOf(zoomView.getX()));
Log.d("VIEW GET Y IS ",String.valueOf(zoomView.getY()));
ObjectAnimator scaleDownX = ObjectAnimator.ofFloat(zoomView, "scaleX", (float)(zoomTillX));
ObjectAnimator scaleDownY = ObjectAnimator.ofFloat(zoomView, "scaleY",(float)(zoomTillY));
List<Animator> oaList = new ArrayList<Animator>();
oaList.add(scaleDownX);
oaList.add(scaleDownY);
AnimatorSet ani = new AnimatorSet();
ani.playTogether(oaList);
ani.setDuration(500);
ani.start();
}else{
handler.postDelayed(this,300);
}
}
},500);
}
});
}
}
This is how it looks finally.

That can be done via ValueAnimator.
Having this layout as the content of activity:
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/content_frame"
android:layout_width="match_parent"
android:layout_height="match_parent">
<View
android:id="#+id/view"
android:layout_width="170dp"
android:layout_height="170dp"
android:background="#3143ff"/>
</FrameLayout>
And in activity's onCreate():
final View view = findViewById(R.id.view);
final View contentView = findViewById(R.id.content_frame);
contentView.setOnClickListener(v -> {
final int screenWidth = contentView.getWidth();
final int screenHeight = contentView.getHeight();
ValueAnimator widthAnimator = ValueAnimator.ofInt(view.getWidth(), screenWidth);
ValueAnimator heightAnimator = ValueAnimator.ofInt(view.getHeight(), screenHeight);
widthAnimator.setDuration(1500);
heightAnimator.setDuration(1500);
widthAnimator.addUpdateListener(animation -> {
view.getLayoutParams().width = (int) animation.getAnimatedValue();
view.requestLayout();
});
heightAnimator.addUpdateListener(animation -> {
view.getLayoutParams().height = (int) animation.getAnimatedValue();
view.requestLayout();
});
widthAnimator.start();
heightAnimator.start();
});
This will be the result:
Transitions API
We've implemented this animation ourselves. But why won't we let the system take care of building all this animators?
There's a Transitions API, which will take the heavy lifting for us. All we have to do, is to ask the framework to detect layout changes, create appropriate animators and run the animations.
So, all the code above can be changed to following, which will result in exactly same output:
contentView.setOnClickListener(v -> {
final int screenWidth = contentView.getWidth();
final int screenHeight = contentView.getHeight();
// Uncomment this, if you want Transitions API to run default animation
// TransitionManager.beginDelayedTransition(contentView);
Transition autoTransition = new AutoTransition();
autoTransition.setDuration(1500);
// With this overload you can control actual transition animation
TransitionManager.beginDelayedTransition(contentView, autoTransition);
// After `beginDelayedTransition()` function perform changes to the layout
// Transitions framework will detect those changes and perform appropriate animations
view.getLayoutParams().width = screenWidth;
view.getLayoutParams().height = screenHeight;
view.requestLayout();
view.invalidate();
});

How to blur the background image of the main layout in android?

I just want to make the background image to look blur(like defocus),I used alpha but it was not only setting alpha to my background image but also to the whole content...Is there any way that I can set blur effect only to my background image!!!..
need help thanks in advance!!..

Please use below tutorial for blur background
NavigationDrawer :
https://github.com/charbgr/BlurNavigationDrawer
Fragment:
https://github.com/tvbarthel/BlurDialogFragment
Image : If you want to blur an image in layout :
https://github.com/kikoso/android-stackblur
Layout:
https://github.com/PomepuyN/BlurEffectForAndroidDesign
public class MainActivity extends Activity {
private static final String BLURRED_IMG_PATH = "blurred_image.png";
private static final int TOP_HEIGHT = 700;
private ListView mList;
private ImageView mBlurredImage;
private View headerView;
private ImageView mNormalImage;
private ScrollableImageView mBlurredImageHeader;
private Switch mSwitch;
private float alpha;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS);
setContentView(R.layout.activity_main);
// Get the screen width
final int screenWidth = ImageUtils.getScreenWidth(this);
// Find the view
mBlurredImage = (ImageView) findViewById(R.id.blurred_image);
mNormalImage = (ImageView) findViewById(R.id.normal_image);
mBlurredImageHeader = (ScrollableImageView) findViewById(R.id.blurred_image_header);
mSwitch = (Switch) findViewById(R.id.background_switch);
mList = (ListView) findViewById(R.id.list);
// prepare the header ScrollableImageView
mBlurredImageHeader.setScreenWidth(screenWidth);
// Action for the switch
mSwitch.setOnCheckedChangeListener(new OnCheckedChangeListener() {
#Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
if (isChecked) {
mBlurredImage.setAlpha(alpha);
} else {
mBlurredImage.setAlpha(0f);
}
}
});
// Try to find the blurred image
final File blurredImage = new File(getFilesDir() + BLURRED_IMG_PATH);
if (!blurredImage.exists()) {
// launch the progressbar in ActionBar
setProgressBarIndeterminateVisibility(true);
new Thread(new Runnable() {
#Override
public void run() {
// No image found => let's generate it!
BitmapFactory.Options options = new BitmapFactory.Options();
options.inSampleSize = 2;
Bitmap image = BitmapFactory.decodeResource(getResources(), R.drawable.image, options);
Bitmap newImg = Blur.fastblur(MainActivity.this, image, 12);
ImageUtils.storeImage(newImg, blurredImage);
runOnUiThread(new Runnable() {
#Override
public void run() {
updateView(screenWidth);
// And finally stop the progressbar
setProgressBarIndeterminateVisibility(false);
}
});
}
}).start();
} else {
// The image has been found. Let's update the view
updateView(screenWidth);
}
String[] strings = getResources().getStringArray(R.array.list_content);
// Prepare the header view for our list
headerView = new View(this);
headerView.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT, TOP_HEIGHT));
mList.addHeaderView(headerView);
mList.setAdapter(new ArrayAdapter<String>(this, R.layout.list_item, strings));
mList.setOnScrollListener(new OnScrollListener() {
#Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
}
/**
* Listen to the list scroll. This is where magic happens ;)
*/
#Override
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
// Calculate the ratio between the scroll amount and the list
// header weight to determinate the top picture alpha
alpha = (float) -headerView.getTop() / (float) TOP_HEIGHT;
// Apply a ceil
if (alpha > 1) {
alpha = 1;
}
// Apply on the ImageView if needed
if (mSwitch.isChecked()) {
mBlurredImage.setAlpha(alpha);
}
// Parallax effect : we apply half the scroll amount to our
// three views
mBlurredImage.setTop(headerView.getTop() / 2);
mNormalImage.setTop(headerView.getTop() / 2);
mBlurredImageHeader.handleScroll(headerView.getTop() / 2);
}
});
}
private void updateView(final int screenWidth) {
Bitmap bmpBlurred = BitmapFactory.decodeFile(getFilesDir() + BLURRED_IMG_PATH);
bmpBlurred = Bitmap.createScaledBitmap(bmpBlurred, screenWidth, (int) (bmpBlurred.getHeight()
* ((float) screenWidth) / (float) bmpBlurred.getWidth()), false);
mBlurredImage.setImageBitmap(bmpBlurred);
mBlurredImageHeader.setoriginalImage(bmpBlurred);
}
}

Kotlin code, use view effect Library :
1- Add library in build.gradle:
implementation 'com.github.mirrajabi:view-effects:e355a1bac4'
2- Blure the background of root view or view, here Constraint Layout blured by 20%
ViewFilter.getInstance(this)
.setRenderer( BlurRenderer(20))
.applyFilterOnView( root_constraintLayout,
root_constraintLayout )
my github repository for blur background : link

scale animation in DragShadowBuilder canvas during drag and drop

How can I create a custom DragShadowBuilder to animate the scaling of a view thats in the canvas instead of it just scaling to a set size?
For example I have an ImageView that is used for drag and drop and when I press on the ImageView the image needs to grow in the canvas thats used for drag and drop that you would see following your finger while you are dragging it to a drop zone.
I am able to get the image to scale to a set size using the following CustomDragShadowBuilder class found here but is there a way to animate the scaling?
public static class CustomDragShadowBuilder extends View.DragShadowBuilder {
private static final int SCALING_FACTOR = 4;
public CustomDragShadowBuilder(View view) {
super(view);
}
#Override
public void onProvideShadowMetrics(Point shadowSize, Point shadowTouchPoint) {
View v = getView();
final int width = v.getWidth() * SCALING_FACTOR;
final int height = v.getHeight() * SCALING_FACTOR;
shadowSize.set(width, height);
shadowTouchPoint.set(width / 2, height / 2);
}
#Override
public void onDrawShadow(Canvas canvas) {
canvas.scale(SCALING_FACTOR, SCALING_FACTOR);
getView().draw(canvas);
}
}

best solution I found is to animate the scale before start the dragging, something like that:
final View yourView;
ObjectAnimator scaleX = ObjectAnimator.ofFloat(yourView, "scaleX",4f);
ObjectAnimator scaleY = ObjectAnimator.ofFloat(yourView, "scaleY",4f);
AnimatorSet animSetXY = new AnimatorSet();
animSetXY.playTogether(scaleX, scaleY);
animSetXY.setDuration(duration);
final View.DragShadowBuilder shadow = new View.DragShadowBuilder(this);
animSetXY.addListener(new AnimatorListenerAdapter() {
#Override
public void onAnimationEnd(Animator animation) {
super.onAnimationEnd(animation);
v.startDrag(dragData, // the data to be dragged
new CustomDragShadowBuilder(yourView) , // the drag shadow builder
null,
0 // flags (not currently used, set to 0)
);
}
});
animSetXY.start();

Android: How to make a gridview of equal proportions within the Java code

I am working on an application which has a main screen with a gridview layout.
As it stands currently, I am hardcoding in DP numbers for the height and width of the boxes, which I obviously do not want to do. How to I create code that will determine the users' screen size and match the boxes accordingly so that someone with a large phone like a note will view the same thing as someone on a droid mini? IE, when hardcoding to 500dp on each side, it looks like this:
But my goal is to make it look like this on every screen size:
Currently, this is the Java code I have:
public class ActivityAdapter extends BaseAdapter {
//Array of Icons that will be used as menu choices
public static int[] imageOptions = {
R.drawable.vacation_quota, //Position 0
R.drawable.revenue_deficit, //Position 1
//+ many more options...
};
private Context context;
//Constructor to pass context back to Main class
public ActivityAdapter(Context applicationContext) {
context = applicationContext;
}
//Number of elements to be displayed on the grid
#Override
public int getCount() {
return imageOptions.length;
}
#Override
public View getView(int position, View convertView, ViewGroup arg2) {
ImageView iv;
if(convertView != null){
iv = (ImageView) convertView;
} else {
iv = new ImageView(context);
//Here I have it hard coded to match a 480px width. Here is where I need to change it, just not sure how
iv.setLayoutParams(new GridView.LayoutParams(240, 240));
iv.setScaleType(ScaleType.CENTER_CROP); //Center the cropping
}
//Sets the image to correspond to its position within the array.
iv.setImageResource(imageOptions[position]);
return iv;
}
Any ideas? I think logically I want to figure out the screen dimensions and use them to make the image dimensions match, just not sure how. Research from other threads has not helped a great deal so hoping I can get a simpler answer here with code posting.

You should get the screen width and height. Then use these values to dynamically set height and width for each cell

Try this code-
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle state) {
setContentView(new ViewGroup(this) {
private RelativeLayout[] items = new RelativeLayout[9];
private int width, height, itemWidth, itemHeight;
{
Random r = new Random();
for (int i = 0; i < 9; i++) {
items[i] = new RelativeLayout(getContext());
float[] hsv = new float[] {360 * r.nextFloat(), .50f, .75f};
items[i].setBackgroundColor(Color.HSVToColor(hsv));
addView(items[i]);
// UPDATE ////////////////////////////////////
ImageView image = new ImageView(getContext());
switch (i) {
case 0: // top left
case 1: // top center
case 2: // top right
case 3: // center left
case 4: // center center
case 5: // center right
case 6: // bottom left
case 7: // bottom center
case 8: // bottom right
image.setImageResource(R.drawable.ic_launcher);
break;
}
image.setScaleType(ScaleType.FIT_XY);
image.setLayoutParams(new RelativeLayout.LayoutParams(
RelativeLayout.LayoutParams.MATCH_PARENT,
RelativeLayout.LayoutParams.MATCH_PARENT
));
items[i].addView(image);
//////////////////////////////////////////////
}
}
#Override
protected void onMeasure(int wMS, int hMS) {
width = MeasureSpec.getSize(wMS);
height = MeasureSpec.getSize(hMS);
itemWidth = width / 3;
itemHeight = height / 3;
wMS = MeasureSpec.makeMeasureSpec(itemWidth, MeasureSpec.EXACTLY);
hMS = MeasureSpec.makeMeasureSpec(itemHeight, MeasureSpec.EXACTLY);
measureChildren(wMS, hMS);
setMeasuredDimension(width, height);
}
#Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
for (int i = 0; i < 9; i++) {
l = itemWidth * (i % 3);
t = itemHeight * (i / 3);
r = l + itemWidth;
b = t + itemHeight;
items[i].layout(l, t, r, b);
}
}
});
super.onCreate(state);
}
}
Output-
Edit-
For creating scrollable grid view see this http://www.androidhive.info/2012/02/android-gridview-layout-tutorial/

I ended up not able to use some of the recommendations here and had to use a deprecated method to retain my app structure. The code specifically that was added to mine was:
iv = new ImageView(context);
WindowManager wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
Display display = wm.getDefaultDisplay();
float width2 = display.getWidth();
int length = (int) (width2/2);
iv.setLayoutParams(new GridView.LayoutParams(length, length));
With this, the height and width would crop to the right size depending on the size of the screen.

android: setting a button programmatically using setX and setY

public class Game_collecting_view extends View
{
Button image_boy;
private static final int BOY_DIAMETER = 200; // initial spot size
int boy_width =0;
int boy_height =0;
public void setGame_collecting(Game_collecting mGame_collecting)
{
this.mGame_collecting = mGame_collecting;
}
// constructs a new View
public Game_collecting_view(Context context, RelativeLayout parentLayout)
{
super(context);
resources = context.getResources(); // save Resources for loading external values
layoutInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
// get references to various GUI components
relativeLayout = parentLayout;
spotHandler = new Handler(); // used to add spots when game starts
}
#Override
protected void onSizeChanged(int width, int height, int oldw, int oldh)
{
viewWidth = width; // save the new width
viewHeight = height; // save the new height
}
public void set_boy()
{
final Button boy = (Button) layoutInflater.inflate(R.layout.untouched, null);
boy.setX(viewWidth /2);
boy.setY(viewHeight - BOY_DIAMETER);
boy.setPadding(0,0,0,0);
boy.setBackgroundResource(R.drawable.blue);
boy.setLayoutParams(new RelativeLayout.LayoutParams(BOY_DIAMETER, BOY_DIAMETER));
relativeLayout.addView(boy); // add spot to the screen
Toast.makeText(getContext(), "set_boy\nviewWidth=" +viewHeight +"\nviewHeight=" +viewHeight, Toast.LENGTH_SHORT).show();
boy.setOnClickListener
(
new OnClickListener()
{
public void onClick(View v)
{
touchedSpot(boy);
}
}
);
}
public void resume(Context context)
{
resetGame();
}
public void resetGame()
{
for (int i = 1; i <= INITIAL_SPOTS; ++i)
{
spotHandler.postDelayed(addSpotRunnable, i * SPOT_DELAY);
generate_text();
}
set_boy();
}
private Runnable addSpotRunnable = new Runnable()
{
public void run()
{
addNewSpot(); // add a new spot to the game
}
};
Objective:
I would like to set the boy icon at the bottom middle of the screen.
The boy icon is set at this way for later dynamic interface (swipe the screen to the right the boy icon will move to the right, vice versa)
Observation:
The toast reports both the viewWidth and viewHeight =0, and the boy icon appears at 0,0 (left upper corner). If I set the setY(viewHeight + BOY_DIAMETER), the boy icon will be located at (0, 200).
Question:
I would like to ask why the viewWidth and viewHeight both report 0. How could the onSizeChanged be called immediately such that the boy icone could be set at the bottom center of the screen?
Thanks!!

The location is null until Android has calculated their positions. You can retrieve the height and width like this:
image_boy.getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
#Override
public void onGlobalLayout() {
int height = image_boy.getHeight();
int width = image_boy.getWidth();
//these values won't be null
}
});

set layout param for setting the view position