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How to drag a RecyclerView (or ALL of its items) horizontally?

I have a RecyclerView in Android Studio with items within it, and instead of swiping horizontally to a new activity, I'd like to swipe left/right, have the entire RecyclerView (or all of its items, either way, since the overall effect would appear similar) move with my finger. Once the items (or RecyclerView) leave the screen at a threshold (for example, 50%), then I'd like to initiate an animation of new items sliding in.
So far, I have the animation for the items sliding in but cannot:
Get all items or the entire RecyclerView to be dragged by by finger
Once that's accomplished, calculate the percentage of the items/view is offscreen to invoke a function.
Thanks in advance
EDIT:
In my main activity, I already have an onTouchListener to register swiping and each of my items are clickable, but I want to be able to "animate" the items moving left offscreen when I swipe left
An example of my code:
public class MainActivity extends AppCompatActivity {
// Set up layout and such...
...
Recyclerview recyclerview = findViewById(R.id.mRecyclerview);
// Set layout manager and adapter...
...
recyclerview.setOnTouchListener(new SwipeListener(MainActivity.this) {
#Override
public void onSwipeRight() {
super.OnSwipeRight();
swipeRightAnimation();
}
#Override
public void onSwipeLeft() {...}
...
});
/* How do I animate items moving left when swiping right and vice versa?
Inside of SwipeListener? By implementing a new listener? */
}
EDIT2:
I tried this (acting on the parent layout instead of the RecyclerView), but the overall view seems to grow/shrink symmetrically rather than move left or right, any suggestions?
public class HorizontalDragListener implements View.OnTouchListener {
private Context context;
private int x;
private int dXLeft;
private int dXRight;
private DrawerLayout.LayoutParams layoutParams;
public HorizontalDragListener(Context context) {
this.context = context;
}
#Override
public boolean onTouch(View view, MotionEvent motionEvent) {
// Get position information
x = (int) motionEvent.getRawX();
y = (int) motionEvent.getRawY();
// Detect movements
switch (motionEvent.getAction() & MotionEvent.ACTION_MASK) {
case (MotionEvent.ACTION_DOWN): {
layoutParams = (DrawerLayout.LayoutParams) view.getLayoutParams();
dXLeft = x - layoutParams.leftMargin;
dXRight = layoutParams.rightMargin - x;
break;
}
case (MotionEvent.ACTION_MOVE): {
// move object
layoutParams = (DrawerLayout.LayoutParams) view.getLayoutParams();
layoutParams.leftMargin = x - dXLeft;
layoutParams.rightMargin = x + dXRight;
view.setLayoutParams(layoutParams);
break;
}
}
// Update view
view.invalidate();
return true;
}
}

how to add touch pointer to aplication?

I'm developing simple drawing application and I was wondering if it is possible to add visible pointer when touching canvas? What I mean is something similar to mouse indicator on PC. The reason for that is - when using eraser it is not visible where exactly your touch is registered and with the pointer, it would help (especially when using finger touch, because the pen is quite precise). I've tried with other similar topics but none of them answered the question.

taken from this pos :
How to programmatically enable "show touches" option in Android?
• enable show touches:
Settings.System.putInt(context.getContentResolver(),
"show_touches", 1);
• To disable show touches:
Settings.System.putInt(context.getContentResolver(),
"show_touches", 0);
Remember to add android.permission.WRITE_SETTINGS to your Manifest.
EDIT:
here is a DrawView.java that implements View.OnTouchListener and defines multiple draw modes. however it lacks the indicators.
in main activity inside setListener for the DrawView you override onStartDrawing method: here you can decide whether or not to show an indicator and how to style it depending on DrawView's current mode ( pen ,eraser etc ) and on the other interface methodes move the indicator if its visible and hide it when drawing ends. check the code:
mDrawView.setOnDrawViewListener(new DrawView.OnDrawViewListener() {
#Override public void onStartDrawing() {
canUndoRedo();
// decide whether or not to show an
// indicator and style it depending on
// mDrawView's attributes and current drawing mode
setIndicator(mDrawView.getDrawingMode(),mDrawView.getDrawWidth());
}
#Override
public void onMove(MotionEvent motionEvent) {
if(isIndicatorVisible){
indicatorView.animate()
.x(motionEvent.getX())
.y(motionEvent.getY())
.setDuration(0)
.start();
}
}
#Override public void onEndDrawing() {
canUndoRedo();
//hide indicator here
if (isIndicatorVisible){
indicatorView.setVisibility(View.GONE);
isIndicatorVisible = false;
}
}
here is the edits that i add to DrawView.java :
defined new interface method void onMove(MotionEvent motionEvent)
public interface OnDrawViewListener {
void onStartDrawing();
void onEndDrawing();
void onClearDrawing();
void onRequestText();
void onMove(MotionEvent motionEvent); // added this method
}
called the new method inside onToch:
case MotionEvent.ACTION_MOVE:
onDrawViewListener.onMove(motionEvent); // added this line
mDrawMoveHistory.get(mDrawMoveHistory.size() - 1).setEndX(motionEvent.getX()).setEndY(motionEvent.getY());
if (mDrawingTool == DrawingTool.PEN || mDrawingMode == DrawingMode.ERASER) {
mDrawMoveHistory.get(mDrawMoveHistory.size() - 1).getDrawingPathList()
.get(mDrawMoveHistory.get(mDrawMoveHistory.size() - 1).getDrawingPathList().size() - 1)
.lineTo(motionEvent.getX(), motionEvent.getY());
}
invalidate();
break;
here's setIndicator method :
private void setIndicator(DrawingMode drawingMode, int drawWidth) {
if (drawingMode == DrawingMode.ERASER){
RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(drawWidth, drawWidth);
indicatorView.setLayoutParams(params);
GradientDrawable border = new GradientDrawable();
border.setStroke(1, 0xFF000000); //black border with full opacity
if(Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN) {
indicatorView.setBackgroundDrawable(border);
} else {
indicatorView.setBackground(border);
}
indicatorView.setVisibility(View.VISIBLE);
isIndicatorVisible = true;
}
}

Add image to location where user click on Layout

I am trying to add image to the point (X,Y) on Layout i have created dynamicaly.
I want to add the imageview on exact user clicked location. But the image is not placed on correct location when clicked.
here is my code
final LinearLayout layoutColumnBoxes = new LinearLayout(getParent());
layoutColumnBoxes.setBackgroundColor(Color.GREEN);
layoutColumnBoxes.setId(counterIdForBoxes);
layoutColumnBoxes.setLayoutParams(layoutParamsColumns);
layoutColumnBoxes.setOnTouchListener(new View.OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
Toast.makeText(getParent(),"Event="+event.getX()+"Event Y = "+event.getY(),Toast.LENGTH_SHORT).show();
return false;
}
});
layoutColumnBoxes.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
ImageView imageView = new ImageView(getParent());
imageView.setImageResource(R.drawable.crack);
LinearLayout lay = (LinearLayout) view.findViewById(v.getId());
lay.addView(imageView);
// Toast.makeText(getParent(),"Clicked View Id is="+v.getId(),Toast.LENGTH_SHORT).show();
}
});
Please help.

See I know what you're trying to say cause I too had this problem a few months back when developing an application. When you click a point on the screen the position of the imageview is not close to the way you clicked it right?
the things I did were
1) remove the excess space around your image.
This is optional. The only reason I stated this was because it depends on the type of image in your image view cause later you will be placing the image based on the top left corner of the imageview.
2) if your loading the images from the drawable folder make sure that you have the right size image in the right folder. This is IMPORTANT. if you screw up the sizes, android is going to alter the size and location of your images based on when your touch is based on the screen.
3) you need to set the margins of your image view properly. After hours of googling I came up with the following first you'll need to get half the height and width of your imageview, use imageview.getMeasuredHeight() / 2 and imageview.getMeasuredWidth() / 2 (Call these imgH and imgW respectively for explanation purposes)
the later in your OnTouchListener you'll have to set the top left margin of your imageview (the methods vary on the type of layout you use). This is done by setting the top margin at "event.getY - imgH" and the left margin at "event.getX - imgW"
I have an app in the playstore which uses this feature, you can check it here .
I hope this has solved your problem :) if it hasn't then don't hesitate to speak your doubts.

this code work for me:
public class MainActivity extends ActionBarActivity {
float x, y;
RelativeLayout rl;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
getActionBar().hide();
rl = (RelativeLayout) findViewById(R.id.root_view);
rl.setOnTouchListener(new View.OnTouchListener() {
#Override
public boolean onTouch(View view, MotionEvent motionEvent) {
if (motionEvent.getAction() == MotionEvent.ACTION_DOWN) {
// rl.removeView(iv);
x = motionEvent.getX();
y = motionEvent.getY();
setImageLocation(x, y);
//rl.addView(iv);
}
return false;
}
});
}
public void setImageLocation(float x, float y) {
ImageView newImage;
RelativeLayout.LayoutParams newparams;
newparams = new RelativeLayout.LayoutParams(20, 20);
newparams.setMargins((int) (x-rl.getPaddingLeft()), (int) (y-rl.getPaddingTop()), 0, 0);
newImage = new ImageView(this);
newImage.setLayoutParams(newparams);
newImage.setImageResource(R.drawable.clock);
rl.addView(newImage);
}
}
activity_main.xml layout only has one relativeLayout that has full screen size(match parent)

How to find all pixels touched on an image view?

On my app I have an ImageView which I turned into a Bitmap for editing. I need to detect which pixels on the ImageView were touched by the user. In addition, if the user draws a line with his finger, I need to know all the pixels that were touched in order to change them. How do I detect which pixels were touched?

Ok Jonah, here are some directions for you.
I guess you want that blending effect to react quickly to user input so first thing you'd better go for a custom SurfaceView instead of a ImageView because it is more suitable for drawing high frame rate animations required in 2D action games and animations. I strongly recommend you to read this guide; giving special attention to the part about the use of SurfaceView, before going any further. You will basically need to create a class that extends SurfaceView and implements SurfaceHolder.Callback. This view will then be responsible to listen for user touch events and to render the frames to animate the blending effect.
Take a look at following code as a reference:
public class MainView extends SurfaceView implements SurfaceHolder.Callback {
public MainView(Context context, AttributeSet attrs) {
super(context, attrs);
SurfaceHolder holder = getHolder();
holder.addCallback(this); // Register this view as a surface change listener
setFocusable(true); // make sure we get key events
}
#Override
public boolean onTouchEvent(MotionEvent event) {
super.onTouchEvent(event);
// Check if the touch pointer is the one you want
if (event.getPointerId(event.getActionIndex()) == 0) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
// User touched screen...
case MotionEvent.ACTION_CANCEL:
// User dragged his finger out of the view bounds...
case MotionEvent.ACTION_UP:
// User raised his finger...
case MotionEvent.ACTION_MOVE:
// User dragged his finger...
// Update the blending effect bitmap here and trigger a frame redraw,
// if you don't already have an animation thread to do it for you.
return true;
}
return false;
}
/*
* Callback invoked when the Surface has been created and is ready to be
* used.
*/
public void surfaceCreated(SurfaceHolder holder) {
// You need to wait for this call back before attempting to draw
}
/*
* Callback invoked when the Surface has been destroyed and must no longer
* be touched. WARNING: after this method returns, the Surface/Canvas must
* never be touched again!
*/
public void surfaceDestroyed(SurfaceHolder holder) {
// You shouldn't draw to this surface after this method has been called
}
}
Then use it on the layout of your "drawing" activity like this:
<com.xxx.yyy.MainView
android:id="#+id/main_view"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
To draw to this surface you need the following code:
Canvas c = null;
try {
c = mSurfaceHolder.lockCanvas(null);
synchronized (mSurfaceHolder) {
if (c != null)
c.drawBitmap(blendingImage, 0, 0, null); // Render blending effect
}
} catch (Exception e) {
Log.e("SurfaceView", "Error drawing frame", e);
} finally {
// do this in a finally so that if an exception is thrown
// during the above, we don't leave the Surface in an
// inconsistent state
if (c != null) {
mSurfaceHolder.unlockCanvasAndPost(c);
}
}
A fully functional example would be impractical to put in an answer so I recommend you to download the Lunar Lander sample game from Google for a full working example. Note however, that you won't need a game animation thread (although it won't hurt having one), like the one coded in the Lunar Lander sample, if all you need is the blending effect. The purpose of that thread is to create a game loop in which game frames are constantly generated to animate objects that may or may not depend on user input. In your case, all you need is to trigger a frame redraw after processing each touch event.
EDIT: The following code are fixes to get the code you've provided in the comments, working.
Here are the changes to MainActivity:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// put pics from drawables to Bitmaps
Resources res = getResources();
BitmapDrawable bd1 = (BitmapDrawable) res.getDrawable(R.drawable.pic1);
// FIX: This block makes `operation` a mutable bitmap version of the loaded resource
// This is required because immutable bitmaps can't be changed
Bitmap tmp = bd1.getBitmap();
operation = Bitmap.createBitmap(tmp.getWidth(), tmp.getHeight(), Bitmap.Config.ARGB_8888);
Canvas c = new Canvas(operation);
Paint paint = new Paint();
c.drawBitmap(tmp, 0f, 0f, paint);
BitmapDrawable bd2 = (BitmapDrawable) res.getDrawable(R.drawable.pic2);
bmp = bd2.getBitmap();
myView = new MainView(this, operation, bmp);
FrameLayout preview = (FrameLayout) findViewById(R.id.preview);
preview.addView(myView);
}
...
Here are the changes to the MainView class:
public class MainView extends SurfaceView implements Callback {
private SurfaceHolder holder;
private Bitmap operation;
private Bitmap bmp2;
private boolean surfaceReady;
// took out AttributeSet attrs
public MainView(Context context, Bitmap operation, Bitmap bmp2) {
super(context);
this.operation = operation;
this.bmp2 = bmp2;
holder = getHolder(); // Fix: proper reference the instance variable
holder.addCallback(this); // Register this view as a surface change
// listener
setFocusable(true); // make sure we get key events
}
// Added so the blending operation is made in one place so it can be more easily upgraded
private void blend(int x, int y) {
if (x >= 0 && y >= 0 && x < bmp2.getWidth() && x < operation.getWidth() && y < bmp2.getHeight() && y < operation.getHeight())
operation.setPixel(x, y, bmp2.getPixel(x, y));
}
// Added so the drawing is now made in one place
private void drawOverlays() {
Canvas c = null;
try {
c = holder.lockCanvas(null);
synchronized (holder) {
if (c != null)
c.drawBitmap(operation, 0, 0, null); // Render blending
// effect
}
} catch (Exception e) {
Log.e("SurfaceView", "Error drawing frame", e);
} finally {
// do this in a finally so that if an exception is thrown
// during the above, we don't leave the Surface in an
// inconsistent state
if (c != null) {
holder.unlockCanvasAndPost(c);
}
}
}
#Override
public boolean onTouchEvent(MotionEvent event) {
super.onTouchEvent(event);
if (!surfaceReady) // No attempt to blend or draw while surface isn't ready
return false;
// Check if the touch pointer is the one you want
if (event.getPointerId(event.getActionIndex()) == 0) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
// User touched screen. Falls through ACTION_MOVE once there is no break
case MotionEvent.ACTION_MOVE:
// User dragged his finger...
blend((int) event.getX(), (int) event.getY());
}
// Update the blending effect bitmap here and trigger a frame
// redraw,
// if you don't already have an animation thread to do it for you.
drawOverlays();
return true;
}
return false;
}
/*
* Callback invoked when the Surface has been created and is ready to be
* used.
*/
public void surfaceCreated(SurfaceHolder holder) {
surfaceReady = true;
drawOverlays();
}
/*
* Callback invoked when the Surface has been destroyed and must no longer
* be touched. WARNING: after this method returns, the Surface/Canvas must
* never be touched again!
*/
public void surfaceDestroyed(SurfaceHolder holder) {
// You shouldn't draw to this surface after this method has been called
surfaceReady = false;
}
#Override
public void surfaceChanged(SurfaceHolder holder, int format, int width,
int height) {
// TODO Auto-generated method stub
}
}
This code works for me. I just hope I didn't forget anything =:)
Let me know if you still have trouble, ok?

So the answer to this is that you're going to have to be a little clever, but it really shouldn't be so bad. Instead of posting all the code to do what you want to do, I'll give you a link here and an explanation.
So by managing the touch events of an application, you can figure out the average coordinates of a touch event. Using that information you can determine the center of all the pixels touched and continue to track that as a line is drawn with the finger. To track a straight line use the
case MotionEvent.ACTION_DOWN:
case MotionEvent.ACTION_UP:
clauses to determine the start and end of the line. If you want to track a line that is not straight and drawn, you're going to need a little more tracking using
case MotionEvent.ACTION_MOVE:
and that should get you fairly started. You may need a little bit of logic to deal with the fact that you will be drawing a very thin line and I suspect that's not quite what you're going for. Maybe it is though. Either way this should be a good place to get started.
EDIT
In regards to your first comment, here is a link you can use for an example. I have to make a small disclaimer though. To get all of the pieces to work together correctly, it may not seem that simple at first. I assure you that this is one of the simplest examples and breaks the tutorial into sections.
For what you would like to do, I think you'll want to pay particular attention to section 2 (no to be confused with step 2):
2. Facilitate Drawing
I suggest this because it shows different ways to use information form the TouchEvent. The things included in section 1 will explain a little bit about the environment to setup displaying a TouchEvent's captured data whereas section 3 is mostly about aesthetics. This may not directly answer your question, but I suspect it will get you where you need to be.
Happy coding! Leave a comment if you have any questions.

Add an image as background and put other images on top of it

I am creating an image by using Canvas- and Bitmap class. I want to set it as a background for the user. Then I want to add some more images on top of it.
this is the code for image that is supposed to be as background.
ImageView imgMap1 = (ImageView) findViewById(R.id.imgMap1);
imgMap1.setImageDrawable(new BitmapDrawable(Bitmap.createBitmap(bmp, 0, 0, 500, 500)));
and this is the code to make it as background:
LinearLayout ll = new LinearLayout(this);
ll.setBackgroundResource(R.drawable.nn);
this.setContentView(ll);
The Problem here is: When I set it as background, I can't see the other photo anymore.
How can I do this?
Thanks in advance.
The other Images are added in the Layout. they are movable by finger touch. user can reposition them by finger.
ImageView i1 = (ImageView) findViewById(R.id.Image1);
ImageView i2 = (ImageView) findViewById(R.id.Image2);

The layout is built from the top down in your XML file, or in the order you add elements in code. It sounds like your other images is being added to the layout first, either as a higher-up element in the XML file, or earlier in your code. You'll need to add the other code as context for a complete answer.

Just noticed that you can directly set Bitmap as your ImageView's content using setImageBitmap(Bitmap bm)See the Android Reference
Then let talk about your question.
First, create your own class extends the View;
Second, load background image and overlay image using Bitmap
Third, invoke onTouch event, so that the onDraw method will automatically redraw the overlay image using the coordinates returned by onTouch
Something like:
public class dragndrop extends Activity {
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
// using this to load your background image
BitmapFactory.Options opt = new BitmapFactory.Options();
opt.inPreferredConfig = Bitmap.Config.RGB_565; // this is not a must
bmBackground = BitmapFactory.decodeFile(filePath, opt);
super.onCreate(savedInstanceState);
DrawView dv = new DrawView(dragndrop.this);
setContentView(dv);
}
public class DrawView extends View {
Point coordinate;
public DrawView(Context context) {
super(context);
setFocusable(true); //necessary for getting the touch events
}
#Override
protected void onDraw(Canvas canvas) {
// assume you have already load your background image as bitmap
canvas.drawBitmap(bmBackground, 0, 0, null);
// assume bm is the overlay image you need to put on top,
// the method here will draw the object with the coordinate you give
canvas.drawBitmap(bm, coordinate.x, coordinate.y, null);
}
// events when touching the screen
public boolean onTouchEvent(MotionEvent event) {
int eventaction = event.getAction();
int x = (int)event.getX();
int y = (int)event.getY();
switch (eventaction ) {
case MotionEvent.ACTION_DOWN:
// add code here to determine the point user touched is within the object or not
break;
}
}
break;
case MotionEvent.ACTION_MOVE: // touch 'n' drag
// pass the touch point to your object
coordinate.x = x;
coordinate.y = y;
break;
case MotionEvent.ACTION_UP:
// touch drop - just do things here after dropping
break;
}
// redraw the canvas
invalidate();
return true;
}
}
}
This is my own snippet, please edit before use, and please let me know when your question is resolved.