@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
// OnLayout.changed isn't a reliable measure of whether or not the size of this view has changed
// neither is onSizeChanged called often enough. Instead, we track changes in size ourselves,
// and
// only invalidate this matrix if we have a new width/height spec
if (widthMeasureSpec != mWidthSpec || heightMeasureSpec != mHeightSpec) {
mWidthSpec = widthMeasureSpec;
mHeightSpec = heightMeasureSpec;
mLayoutChanged = true;
}
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
@Override
public void setImageDrawable(Drawable drawable) {
if (drawable == null) {
drawable = ContextCompat.getDrawable(getContext(), R.drawable.tab_panel_tab_background);
setScaleType(ScaleType.FIT_XY);
mScale = false;
} else {
mScale = true;
setScaleType(ScaleType.FIT_CENTER);
}
super.setImageDrawable(drawable);
}
@Override
public void onDraw(Canvas canvas) {
if (!mScale) {
super.onDraw(canvas);
return;
}
Drawable d = getDrawable();
if (mLayoutChanged) {
int w1 = d.getIntrinsicWidth();
int h1 = d.getIntrinsicHeight();
int w2 = getWidth();
int h2 = getHeight();
float scale = (w2 / h2 < w1 / h1) ? (float) h2 / h1 : (float) w2 / w1;
mMatrix.setScale(scale, scale);
}
int saveCount = canvas.save();
canvas.concat(mMatrix);
d.draw(canvas);
canvas.restoreToCount(saveCount);
}