take the "transparent region" into account for blending
until now it was only used to discard a layer entirely.
we're now reducing the size of the layer if it is still
visible, if possible.
this works for instance when a surfaceView is used and
only the menu bar is displayed over it.
Change-Id: I3f5527c5cd1e69ecc968272c8948f1513ada8c55
diff --git a/libs/ui/Rect.cpp b/libs/ui/Rect.cpp
index 365ea13..b480f3a 100644
--- a/libs/ui/Rect.cpp
+++ b/libs/ui/Rect.cpp
@@ -107,4 +107,35 @@
return result;
}
+Rect Rect::reduce(const Rect& exclude) const {
+ Rect result;
+
+ uint32_t mask = 0;
+ mask |= (exclude.left > left) ? 1 : 0;
+ mask |= (exclude.top > top) ? 2 : 0;
+ mask |= (exclude.right < right) ? 4 : 0;
+ mask |= (exclude.bottom < bottom) ? 8 : 0;
+
+ if (mask == 0) {
+ // crop entirely covers us
+ result.clear();
+ } else {
+ result = *this;
+ if (!(mask & (mask - 1))) {
+ // power-of-2, i.e.: just one bit is set
+ if (mask & 1) {
+ result.right = exclude.left;
+ } else if (mask & 2) {
+ result.bottom = exclude.top;
+ } else if (mask & 4) {
+ result.left = exclude.right;
+ } else if (mask & 8) {
+ result.top = exclude.bottom;
+ }
+ }
+ }
+
+ return result;
+}
+
}; // namespace android