查看外部边界未正确绘制

Question

I'm drawing a tooltip after clicking inside a custom bar chart (created with MPAndroidChart). The view hierarchy is as follows

<LinearLayout>
     <TextView text=Move & Max Pain/>
     <RelativeLayout with 2 textviews>
     <chart
       clipToChildren=false
       clipToPadding=false
     />
</LinearLayout>

While the View is inside the Chart or its inmediate sibling, everthing looks good. But the moment it collides with its sibling, the tooltip is truncated

Using HierarchyViewer I can see that the content is present, but it's not drawn.

In order to get the clipping, I'm using this code inside draw

    @Override
  public void draw(Canvas canvas, float posx, float posy) {
    // take offsets into consideration
    posx += getXOffset();
    posy += getYOffset();

    canvas.save();

    // translate to the correct position and draw
    canvas.translate(posx, posy);

    Rect clipBounds = canvas.getClipBounds();
    clipBounds.inset(0, -getHeight());
    canvas.clipRect(clipBounds, Region.Op.INTERSECT);

    draw(canvas);
    canvas.translate(-posx, -posy);

    canvas.restore();
  }

If I change Op to Region.Op.Replace, the tooltip is draw correctly but it replaces the Toolbar content, instead of scrolling under it.

Answer 1

You'll need the bounds of the area in which you want to be able to draw the tooltip, and I'm assuming that would be a scrollview. Then you can intersect the tooltip bounds with the scroll to work out what the clipping should be; and if it should be drawn at all.

To explain it in code it would be something like this (untested):

Rect scrollViewRect;  // the bounds of your scrollview
Rect tooltipRect;     // the bounds of your tooltip

bool intersects = tooltipRect.intersect(scrollViewRect)
if(intersects)
{
    canvas.clipRect(tooltipRect, Region.Op.REPLACE);
    draw(canvas);
}