Do not resize fullscreen window size if the window size is actually larger than the threshold.

app/src/common/shared/org/mozilla/vrbrowser/ui/widgets/NavigationBarWidget.java

@@ -379,13 +379,19 @@ public void setBrowserWidget(WindowWidget aWidget) {
 
     private void setFullScreenSize() {
         mPlacementBeforeResize.copyFrom(mWindowWidget.getPlacement());
+        final float minScale = WidgetPlacement.floatDimension(getContext(), R.dimen.window_fullscreen_min_scale);
         // Set browser fullscreen size
         float aspect = SettingsStore.getInstance(getContext()).getWindowAspect();
         Media media = SessionStore.get().getFullScreenVideo();
         if (media != null && media.getWidth() > 0 && media.getHeight() > 0) {
             aspect = (float)media.getWidth() / (float)media.getHeight();
         }
-        mWindowWidget.resizeByMultiplier(aspect,1.75f);
+        float scale = mWindowWidget.getCurrentScale();
+        // Enforce min fullscreen size.
+        // If current window area is larger only resize if the aspect changes (e.g. media).
+        if (scale < minScale || aspect != mWindowWidget.getCurrentAspect()) {
+            mWindowWidget.resizeByMultiplier(aspect, Math.max(scale, minScale));
+        }
     }
 
     private void enterFullScreenMode() {

app/src/common/shared/org/mozilla/vrbrowser/ui/widgets/WindowWidget.java

@@ -254,6 +254,20 @@ public void resizeByMultiplier(float aspect, float multiplier) {
         handleResizeEvent(targetWidth, targetHeight);
     }
 
+    public float getCurrentScale() {
+        float currentAspect = getCurrentAspect();
+        float currentWorldHeight = mWidgetPlacement.worldWidth / currentAspect;
+        float currentArea = mWidgetPlacement.worldWidth * currentWorldHeight;
+        float defaultWidth = WidgetPlacement.floatDimension(getContext(), R.dimen.window_world_width);
+        float defaultHeight = defaultWidth / SettingsStore.getInstance(getContext()).getWindowAspect();
+        float defaultArea = defaultWidth * defaultHeight;
+        return currentArea / defaultArea;
+    }
+
+    public float getCurrentAspect() {
+        return (float) mWidgetPlacement.width / (float) mWidgetPlacement.height;
+    }
+
     public int getBorderWidth() {
         return mBorderWidth;
     }

app/src/main/res/values/dimen.xml

@@ -8,6 +8,7 @@
     <item name="window_world_y" format="float" type="dimen">0.2</item>
     <item name="window_world_z" format="float" type="dimen">-4.2</item>
     <item name="browser_children_z_distance" format="float" type="dimen">1.5</item>
+    <item name="window_fullscreen_min_scale" format="float" type="dimen">1.75</item>
 
     <!-- Navigation bar -->
     <dimen name="navigation_bar_width">720dp</dimen>