CODEWITHSUNDEEP
android
numan salati
numan salati

Reputation: 19494

how to get bounds of a scaled view?

It seems that setScaleX or setScaleY don't actually change left,top,right,bottom properties. getX and getY remain unchanged too.

So if I scale a view whats the easiest way to get 4 corner coordinates of the newly scaled view?

I tried getHitRect but that doesn't give me the right answer. I am trying to avoid manually calculating the new bounds based on existing transformations (rotation and scale with pivots factored in).

Upvotes: 1

Views: 2778

Answers (2)

numan salati
numan salati

Reputation: 19494

After exploring the view api, it looks like there is no direct API method that does this.

However you can easily get the new points by grabbing the transform matrix of the view and using that to get the new bounds.

Something like this:

Matrix m = view.getMatrix();
Rect bbox = new Rect();
view.getDrawingRect(bbox); 
m.mapRect(bbox);

If you want to operate on (x,y) coordiantes directly there is a matrix.mapPoints that will achieve the same result.

Upvotes: 4

DeeV
DeeV

Reputation: 36045

I believe if you get the width and height and multiply it by the scales, you'll get the scaled width and height.

int scaledWidth = getWidth() * getScaleX();
int scaledHeight = getHeight() * getScaleY();

int newLeft = getLeft() + (scaledWidth / 2);
int newRight = newLeft + scaledWidth;

int newTop = getTop() + (scaledHeight / 2);
int newBottom = newTop + scaledHeight;

This is assuming that you scaled with a pivot x and y at the center of the view. Things gets far more complicated if you have pivots in strange areas.

Upvotes: 2

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