Hierarchy Viewer Causes Height Changes

Question

this is my first question.

I created a custom component: a RelativeLayout with a TextView at the bottom and two ImageView above, which act as an element with two columns for the histogram. To set the strip height, I get the "available height" in onLayout() , since the container height is minus the label:

 @Override protected void onLayout(boolean changed, int l, int t, int r, int b) { super.onLayout(changed, l, t, r, b); mAvailHeight = getHeight()-findViewById(R.id.label).getHeight(); // it works 

and then assign it (multiplied by 0.-1.) as the layout parameter for ImageView:

  View bar = findViewById(R.id.bigBar); RelativeLayout.LayoutParams rlp = (RelativeLayout.LayoutParams) bar.getLayoutParams(); rlp.height = Math.round((float)mAvailHeight * mBigBarHeight); } 

The variable mBigBarHeight (0.-1.) Can be set using this function:

 public void setBigBarHeight(float value, float max) { mBigBarHeight = value / max; requestLayout(); // invalidate(); // do these help? i find no difference } 

Now. When I add one of these "HistogramBar" to onCreate() and set the heights and labels, everything works as I expect. If I try to change them later, say onClickSomething:

 bar.setBigBarHeight(25, 100); bar.setSmallBarHeight(50, 100); bar.setLabel("jjk"); 

only the label changes. I checked with the Hierarchy Viewer, and actually LayoutParams have changed. If I click, the changes will appear again.

The funny thing is that even if I do a “Load View Hierarchy” from the tool changes, it will be displayed (on the emulator) !! What's happening? This is strange? I want to do this in my code to make it work!

I could not find a similar question. Thanks.

Answer 1

When you load a hierarchy from a tool, relaying / redrawing occurs to measure performance. You probably don't call requestLayout () if you want.