Respect mandatory system gesture insets when computing system bar insets (Android) (#4757)

Author: liannacasper

Ports/Android/src/com/codename1/impl/android/AndroidImplementation.java

@@ -1373,15 +1373,15 @@ public static boolean isImmersive() {
         }
         return isImmersive(getActivity().getWindow());
     }
-    public static boolean isImmersive(Window window) {
-        if (Build.VERSION.SDK_INT >= 35) {
-            // Android 15+ is always immersive (overlay mode by default)
-            return true;
-        }
-        // On Android 34 and below, we can't detect decorFitsSystemWindows
-        // reliably at runtime. So the app must make the decision explicitly.
-        return false;
-    }
+    public static boolean isImmersive(Window window) {
+        if (Build.VERSION.SDK_INT >= 35) {
+            // Android 15+ is always immersive (overlay mode by default)
+            return true;
+        }
+        // On Android 34 and below, we can't detect decorFitsSystemWindows
+        // reliably at runtime. So the app must make the decision explicitly.
+        return false;
+    }
     public static Rect getSystemBarInsets(final View rootView) {
         final Rect result = new Rect(0, 0, 0, 0);
         try {
@@ -1400,14 +1400,34 @@ public static Rect getSystemBarInsets(final View rootView) {
                     .invoke(insets, new Object[]{systemBarsMask});
             if (insetsObject == null) return result;
             Class insetsClass = insetsObject.getClass();
-            int left = ((Integer) insetsClass.getField("left").get(insetsObject)).intValue();
-            int top = ((Integer) insetsClass.getField("top").get(insetsObject)).intValue();
-            int right = ((Integer) insetsClass.getField("right").get(insetsObject)).intValue();
-            int bottom = ((Integer) insetsClass.getField("bottom").get(insetsObject)).intValue();
-            result.set(left, top, right, bottom);
-        } catch (Throwable t) {
-            t.printStackTrace();  // Optional: log this or suppress if expected
-        }
+            int left = ((Integer) insetsClass.getField("left").get(insetsObject)).intValue();
+            int top = ((Integer) insetsClass.getField("top").get(insetsObject)).intValue();
+            int right = ((Integer) insetsClass.getField("right").get(insetsObject)).intValue();
+            int bottom = ((Integer) insetsClass.getField("bottom").get(insetsObject)).intValue();
+            // Include mandatory gesture insets (e.g. gesture navigation handle area).
+            // Some devices expose a larger interaction-protected bottom region here
+            // than in plain system bar insets.
+            try {
+                int mandatoryGesturesMask = ((Integer) typeClass
+                        .getMethod("mandatorySystemGestures")
+                        .invoke(null)).intValue();
+                Object mandatoryInsetsObject = insets.getClass()
+                        .getMethod("getInsets", new Class[]{int.class})
+                        .invoke(insets, new Object[]{mandatoryGesturesMask});
+                if (mandatoryInsetsObject != null) {
+                    Class mandatoryInsetsClass = mandatoryInsetsObject.getClass();
+                    left = Math.max(left, ((Integer) mandatoryInsetsClass.getField("left").get(mandatoryInsetsObject)).intValue());
+                    top = Math.max(top, ((Integer) mandatoryInsetsClass.getField("top").get(mandatoryInsetsObject)).intValue());
+                    right = Math.max(right, ((Integer) mandatoryInsetsClass.getField("right").get(mandatoryInsetsObject)).intValue());
+                    bottom = Math.max(bottom, ((Integer) mandatoryInsetsClass.getField("bottom").get(mandatoryInsetsObject)).intValue());
+                }
+            } catch (Throwable t) {
+                // Ignore if mandatory gesture insets are unavailable.
+            }
+            result.set(left, top, right, bottom);
+        } catch (Throwable t) {
+            t.printStackTrace();  // Optional: log this or suppress if expected
+        }
         return result;
     }