is it possible to find the View that is displayed at a given absolute x/y pixel coord?
Edit: I found a suitable Solution that works great:
private View findViewByCoord(float x, float y){
TextView textView = null;
int[] location = new int[2];
int width = 0;
int height = 0;
for(int reference : cardReference){
textView = (TextView) findViewById(reference);
textView.getLocationOnScreen(location);
width = textView.getWidth();
height = textView.getHeight();
if(location[0] <= x && x <= (location[0] + width) && location[1] <= y && y <= (location[1] + height)){
Log.i("Test", "Card " + textView.getText() + " is pointed");
return textView;
}
}
return null;
}
Where cardReference is an array of integer to Resources (in my case 20 TextViews arranged in a 4 x 5 Matrix):
int[] cardReference = new int[]{R.id.card1_1, R.id.card1_2, R.id.card1_3, R.id.card1_4,
R.id.card2_1, R.id.card2_2, R.id.card2_3, R.id.card2_4,
R.id.card3_1, R.id.card3_2, R.id.card3_3, R.id.card3_4,
R.id.card4_1, R.id.card4_2, R.id.card4_3, R.id.card4_4,
R.id.card5_1, R.id.card5_2, R.id.card5_3, R.id.card5_4};
To speed up performance i would consider to use an array of TextViews then call findViewById() in every Loop.
One 'solution' would be to loop through the parent view's children and check the getLeft() and getTop() coordinates against the X and Y coordinates of your choice. If there is a match, you have your view.
I'd like to hear other alternatives though.
Edit: You'd also have to work out the height/width of the view too in relation to the left and top coordinates given to see if your coordinates are within that range.
Related
I need to get the X and Y position of the "thumb" of a seekbar.
Calling seekbar.getThumb().getBounds() returns me a bound that is relative to the seekbar.
Is there a way I can get the position of the thumb that's relative to the whole screen?
I ended up doing this, not quite sure what to do with the 5 there. Minus 5 is exactly the center of the x position of the dial.
// tipBar is the seekbar.
int [] location = new int[2];
tipBar.getLocationInWindow(location);
int x = location[0] + tipBar.getThumb().getBounds().centerX() + tipBar.getThumbOffset() - 5; // magic 5
int y = location[1] + tipBar.getThumb().getBounds().centerY();
I want to get the coordinate positions of a button in my application.I used the following method.But its not working.Please help.
public Point currentPosition(View view)
{
int[] loc = new int[2];
view.getLocationOnScreen(loc);
int x = loc[0];
int y=loc[1];
Toast.makeText(getApplicationContext(),"coordinate is"+x+","+y,Toast.LENGTH_SHORT).show();
return new Point(loc[0], loc[1]);
}
Also i used this
btn_show.setOnClickListener(new OnClickListener()
{
#Override
public void onClick(View arg0)
{
int x = (int)btn_show.getX();
int y= (int)btn_show.getY();
Toast.makeText(getApplicationContext(), "button x is......"+x,Toast.LENGTH_SHORT ).show();
Toast.makeText(getApplicationContext(), "button y is......"+y,Toast.LENGTH_SHORT ).show();
}
});
The method you use expect integer values as references of R.string.whatever. Cast the getTop() return value to String should work.
Toast.makeText(MainActivity.this, String.valueOf(button1.getTop()), Toast.LENGTH_LONG).show();
To get the x/y of the button (since API 11):
Toast.makeText(MainActivity.this, (int)button1.getX() + ":" + (int)button1.getY(), Toast.LENGTH_LONG).show();
Doc:
The visual x position of this view, in pixels.
For API below 11 you are on the right way: getTop() is the equivalent of getY() but without a possible animation/translation. getLeft() is the quivalent of getX() with the same restriction.
or
You can use View.getTop(), View.getBottom(), View.getLeft(), and View.getRight(). These will return the location of the top, bottom, left and right edge of the View relative to the parent.
or Use
View.getLocationOnScreen()
and/or
getLocationInWindow().
If you are using onTouch lister means use this one.
code for your onTouch method:
float screenX = v.getLeft() + event.getX(); // X in Screen Coordinates
float screenY = v.getTop() + event.getY(); // Y in Screen Coordinates
You have to wait until the View is measured, otherwise it will always return 0. Use an OnGlobalLayoutListener:
view.getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
public void onGlobalLayout() {
int x = view.getLeft();
int y = view.getTop();
}
});
There are a lot of ways to get the coordinator position.
If you want to center a floating button such as a tutorial with tourguide library.
I suggest create this method
public Rect getRectFromAView(View view){
Rect rect=new Rect(); // create a new rect
view.getGlobalRect(rect);// draw the rect
return rect;
}
If I want to get the coordinate position of x or y
Rect rect=getREctFromAView(view);
rect.exactCenterX(); //Return the position X
rect.exactCenterY(); //Return the position Y
This is the case when I try to get the center position of a view.
try :-
float x = button.getX();
float y = button.getY();
At a given pixel location, there is a view. I have the coordinates of the pixel. How to find the id of a view at a given coordinate ?
If you are inside of ViewGroup:
int count = viewgroup.getChildCount();
for (int i = 0; i < count; i++)
{
View view = viewgroup.getChildAt(i);
if (view.getX() == theX && view.getY() == theY)
return view.getId()
}
EDIT (kcoppock): within the for loop, I'd do something like this:
View view = viewgroup.getChildAt(i);
if(!view.getVisibility() == View.VISIBLE) continue;
int[] location = {0, 0};
view.getLocationOnScreen(location);
int right = location[0] + view.getWidth();
int bottom = location[1] + view.getHeight();
Rect bounds = new Rect(location[0], location[1], right, bottom);
if(bounds.contains(coordinatesX, coordinatesY)) return view.getId();
I think something like this should work:
Walk your view hierarchy to find child views (i.e. those with no sub-views) that are Visible.
use View.getLocationOnScreen() on your views to retrieve their location (the top/left window coordinate)
use getMeasuredWidth() / getMeasuredHeight() to get the view width and height
see if your pixel coordinate falls within this rectangle
Given a TextView, is it possible to know at runtime the X and Y coordinates of where it is drawn?
Is it also possible to know the size (width/length) in pixels?
There are getLeft(), getTop(), getWidth(), getHeight() methods for a view, it works for textView too. for more information , see the following link...
getLeft() and getTop() will return you the starting x,y co-ordinates.
http://developer.android.com/reference/android/view/View.html
Coordinates relative to parent
int x = textView.getLeft();
int y = textView.getTop();
Absolute coordinates
int[] location = new int[2];
textView.getLocationOnScreen(location);
int x = location[0];
int y = location[1];
See this answer for more.
Pixel size
int width = textView.getWidth();
int height = textView.getHeight();
Notes
If you are getting (0,0) it could be because you are getting the relative coordinates related to the parent layout (and it is sitting in the top left corner of the parent). It could also be because you are trying to get the coordinates before the view has been laid out (for example, in onCreate()).
Can I get a View's x and y position relative to the root layout of my Activity in Android?
The Android API already provides a method to achieve that.
Try this:
Rect offsetViewBounds = new Rect();
//returns the visible bounds
childView.getDrawingRect(offsetViewBounds);
// calculates the relative coordinates to the parent
parentViewGroup.offsetDescendantRectToMyCoords(childView, offsetViewBounds);
int relativeTop = offsetViewBounds.top;
int relativeLeft = offsetViewBounds.left;
Here is the doc
This is one solution, though since APIs change over time and there may be other ways of doing it, make sure to check the other answers. One claims to be faster, and another claims to be easier.
private int getRelativeLeft(View myView) {
if (myView.getParent() == myView.getRootView())
return myView.getLeft();
else
return myView.getLeft() + getRelativeLeft((View) myView.getParent());
}
private int getRelativeTop(View myView) {
if (myView.getParent() == myView.getRootView())
return myView.getTop();
else
return myView.getTop() + getRelativeTop((View) myView.getParent());
}
Let me know if that works.
It should recursively just add the top and left positions from each parent container.
You could also implement it with a Point if you wanted.
Please use view.getLocationOnScreen(int[] location); (see Javadocs). The answer is in the integer array (x = location[0] and y = location[1]).
View rootLayout = view.getRootView().findViewById(android.R.id.content);
int[] viewLocation = new int[2];
view.getLocationInWindow(viewLocation);
int[] rootLocation = new int[2];
rootLayout.getLocationInWindow(rootLocation);
int relativeLeft = viewLocation[0] - rootLocation[0];
int relativeTop = viewLocation[1] - rootLocation[1];
First I get the root layout then calculate the coordinates difference with the view.
You can also use the getLocationOnScreen() instead of getLocationInWindow().
No need to calculate it manually.
Just use getGlobalVisibleRect like so:
Rect myViewRect = new Rect();
myView.getGlobalVisibleRect(myViewRect);
float x = myViewRect.left;
float y = myViewRect.top;
Also note that for the centre coordinates, rather than something like:
...
float two = (float) 2
float cx = myViewRect.left + myView.getWidth() / two;
float cy = myViewRect.top + myView.getHeight() / two;
You can just do:
float cx = myViewRect.exactCenterX();
float cy = myViewRect.exactCenterY();
You can use `
view.getLocationOnScreen(int[] location)
;` to get location of your view correctly.
But there is a catch if you use it before layout has been inflated you will get wrong position.
Solution to this problem is adding ViewTreeObserver like this :-
Declare globally the array to store x y position of your view
int[] img_coordinates = new int[2];
and then add ViewTreeObserver on your parent layout to get callback for layout inflation and only then fetch position of view otherwise you will get wrong x y coordinates
// set a global layout listener which will be called when the layout pass is completed and the view is drawn
parentViewGroup.getViewTreeObserver().addOnGlobalLayoutListener(
new ViewTreeObserver.OnGlobalLayoutListener() {
public void onGlobalLayout() {
//Remove the listener before proceeding
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
parentViewGroup.getViewTreeObserver().removeOnGlobalLayoutListener(this);
} else {
parentViewGroup.getViewTreeObserver().removeGlobalOnLayoutListener(this);
}
// measure your views here
fab.getLocationOnScreen(img_coordinates);
}
}
);
and then use it like this
xposition = img_coordinates[0];
yposition = img_coordinates[1];
I wrote myself two utility methods that seem to work in most conditions, handling scroll, translation and scaling, but not rotation. I did this after trying to use offsetDescendantRectToMyCoords() in the framework, which had inconsistent accuracy. It worked in some cases but gave wrong results in others.
"point" is a float array with two elements (the x & y coordinates), "ancestor" is a viewgroup somewhere above the "descendant" in the tree hierarchy.
First a method that goes from descendant coordinates to ancestor:
public static void transformToAncestor(float[] point, final View ancestor, final View descendant) {
final float scrollX = descendant.getScrollX();
final float scrollY = descendant.getScrollY();
final float left = descendant.getLeft();
final float top = descendant.getTop();
final float px = descendant.getPivotX();
final float py = descendant.getPivotY();
final float tx = descendant.getTranslationX();
final float ty = descendant.getTranslationY();
final float sx = descendant.getScaleX();
final float sy = descendant.getScaleY();
point[0] = left + px + (point[0] - px) * sx + tx - scrollX;
point[1] = top + py + (point[1] - py) * sy + ty - scrollY;
ViewParent parent = descendant.getParent();
if (descendant != ancestor && parent != ancestor && parent instanceof View) {
transformToAncestor(point, ancestor, (View) parent);
}
}
Next the inverse, from ancestor to descendant:
public static void transformToDescendant(float[] point, final View ancestor, final View descendant) {
ViewParent parent = descendant.getParent();
if (descendant != ancestor && parent != ancestor && parent instanceof View) {
transformToDescendant(point, ancestor, (View) parent);
}
final float scrollX = descendant.getScrollX();
final float scrollY = descendant.getScrollY();
final float left = descendant.getLeft();
final float top = descendant.getTop();
final float px = descendant.getPivotX();
final float py = descendant.getPivotY();
final float tx = descendant.getTranslationX();
final float ty = descendant.getTranslationY();
final float sx = descendant.getScaleX();
final float sy = descendant.getScaleY();
point[0] = px + (point[0] + scrollX - left - tx - px) / sx;
point[1] = py + (point[1] + scrollY - top - ty - py) / sy;
}
Incase someone is still trying to figure this out. This is how you get the center X and Y of the view.
int pos[] = new int[2];
view.getLocationOnScreen(pos);
int centerX = pos[0] + view.getMeasuredWidth() / 2;
int centerY = pos[1] + view.getMeasuredHeight() / 2;
I just found the answer here
It says:
It is possible to retrieve the location of a view by invoking the methods getLeft() and getTop(). The former returns the left, or X, coordinate of the rectangle representing the view. The latter returns the top, or Y, coordinate of the rectangle representing the view. These methods both return the location of the view relative to its parent. For instance, when getLeft() returns 20, that means the view is located 20 pixels to the right of the left edge of its direct parent.
so use:
view.getLeft(); // to get the location of X from left to right
view.getRight()+; // to get the location of Y from right to left
You can use the following the get the difference between parent and the view you interested in:
private int getRelativeTop(View view) {
final View parent = (View) view.getParent();
int[] parentLocation = new int[2];
int[] viewLocation = new int[2];
view.getLocationOnScreen(viewLocation);
parent.getLocationOnScreen(parentLocation);
return viewLocation[1] - parentLocation[1];
}
Dont forget to call it after the view is drawn:
timeIndicator.getViewTreeObserver().addOnGlobalLayoutListener(() -> {
final int relativeTop = getRelativeTop(timeIndicator);
});