Support @left marker

By default cutouts are centered and support a @right marker to allow
them to be right aligned. Let's also support left alignment by
introducing a @left marker.

Test: atest DisplayCutoutTest
Test: manual
Bug: 143222961
Bug: 145707162
Change-Id: Ic5a645bd9f0513f3665f31c8b0f1861585bf30e6
Merged-In: Ic5a645bd9f0513f3665f31c8b0f1861585bf30e6
(cherry picked from commit 6e9636c5e0)

core/java/android/view/DisplayCutout.java

@@ -66,6 +66,7 @@ public final class DisplayCutout {
     private static final String BOTTOM_MARKER = "@bottom";
     private static final String DP_MARKER = "@dp";
     private static final String RIGHT_MARKER = "@right";
+    private static final String LEFT_MARKER = "@left";
 
     /**
      * Category for overlays that allow emulating a display cutout on devices that don't have
@@ -642,6 +643,9 @@ public final class DisplayCutout {
         if (spec.endsWith(RIGHT_MARKER)) {
             offsetX = displayWidth;
             spec = spec.substring(0, spec.length() - RIGHT_MARKER.length()).trim();
+        } else if (spec.endsWith(LEFT_MARKER)) {
+            offsetX = 0;
+            spec = spec.substring(0, spec.length() - LEFT_MARKER.length()).trim();
         } else {
             offsetX = displayWidth / 2f;
         }

core/res/res/values/config.xml

@@ -3194,7 +3194,9 @@
 
          The path is assumed to be specified in display coordinates with pixel units and in
          the display's native orientation, with the origin of the coordinate system at the
-         center top of the display.
+         center top of the display. Optionally, you can append either `@left` or `@right` to the
+         end of the path string, in order to change the path origin to either the top left,
+         or top right of the display.
 
          To facilitate writing device-independent emulation overlays, the marker `@dp` can be
          appended after the path string to interpret coordinates in dp instead of px units.