Android drawing button to canvas with custom view?

Question

How can I draw a button on top of the canvas in a custom view? (Preferably on the mid-right side) Is there something I have to call before doing the button.draw(canvas)?

    public class MyClass extends View {
    public Simulation(Context context) {
            super(context);
            pauseButton.setText("TestButton");
            pauseButton.setClickable(true);
            pauseButton.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
            Log.i(TAG, "Button Pressed!");
            }
            });
    public onDraw(Canvas canvas) {
           super.onDraw(canvas);
           pauseButton.draw(canvas);
    }
    }

Thanks for your time

What is the current situation. Is it drawing atall? or drawing at wrong place? — Ron, Aug 13 '11 at 04:41
It's currently not drawing at all. My guess is that its drawing it underneath the canvas/custom view? — unknownone, Aug 13 '11 at 04:54

score 16 · Accepted Answer · edited May 23 '17 at 11:47

16

You cannot insert a button into canvas. Canvas is an interface for bitmap or a bitmap buffer for a view. You can only draw other bitmap or pixels in it, not insert an object or a widget.

There are some solutions:

as Nikolay suggested, use a FrameLayout and create two layers (views), first your custom view and the second LinerView or RelativeView, which will come on top, where you can have buttons etc
draw an image of a buttun on Canvas then use onTouchEvent in your custom view and test for the coordinates of the touch, then do something... an example for onTouchEvent here: Make certain area of bitmap transparent on touch

edited May 23 '17 at 11:47

Community

1
1

answered Aug 13 '11 at 13:40

Lumis

21,517
8
63
67

How would I add my custom view to the xml file? Thanks for your answer – unknownone Aug 14 '11 at 01:58
1

That is a long story, you have to search for examples...but basically you create a new tag like .... in xml and then create a new class called MyView extends View which has a constructor MyView(Context context, AttributeSet attrs){ super(context, attrs); ....} in this example just add the constructor i mentioned: http://stackoverflow.com/questions/6308106/view-inflation-and-custom-views – Lumis Aug 14 '11 at 08:04

score 6 · Answer 2 · answered Aug 13 '11 at 05:03

6

Why do you need to draw the button yourself? Use a FrameLayout and simply have the button overlayed on your custom view.

answered Aug 13 '11 at 05:03

Nikolay Elenkov

52,576
10
84
84

score -1 · Answer 3 · answered Aug 13 '11 at 05:34

-1

Try this

public onDraw(Canvas canvas) {
       super.onDraw(canvas);
       canvas.save();
       pauseButton.draw(canvas);
       canvas.restore();
}

answered Aug 13 '11 at 05:34

Ron

24,175
8
56
97

Android drawing button to canvas with custom view?

3 Answers3

Linked