Add GalleryHeader avoid notch

app/src/main/java/com/hippo/ehviewer/widget/GalleryHeader.java

@@ -0,0 +1,108 @@
+/*
+ * Copyright 2019 Hippo Seven
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.hippo.ehviewer.widget;
+
+import android.content.Context;
+import android.graphics.Rect;
+import android.os.Build;
+import android.util.AttributeSet;
+import android.util.SparseIntArray;
+import android.view.DisplayCutout;
+import android.view.View;
+import android.widget.FrameLayout;
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.annotation.RequiresApi;
+
+// Offset widgets to avoid notch
+public class GalleryHeader extends FrameLayout {
+
+  private SparseIntArray originalTopMargins = new SparseIntArray();
+  private DisplayCutout displayCutout = null;
+  private int[] location = new int[2];
+  private Rect rect = new Rect();
+
+  public GalleryHeader(Context context, AttributeSet attrs) {
+    super(context, attrs);
+  }
+
+  @RequiresApi(api = Build.VERSION_CODES.P)
+  public void setDisplayCutout(@Nullable DisplayCutout displayCutout) {
+    // Backup top margins
+    if (originalTopMargins.size() == 0) {
+      for (int i = 0; i < getChildCount(); i++) {
+        View child = getChildAt(i);
+        originalTopMargins.append(child.getId(), ((MarginLayoutParams) child.getLayoutParams()).topMargin);
+      }
+    }
+
+    if (displayCutout != null) {
+      // Update top margins
+      if (getWidth() == 0 && getHeight() == 0) {
+        this.displayCutout = displayCutout;
+      } else {
+        updateTopMargins(displayCutout);
+      }
+    } else if (originalTopMargins.size() != 0) {
+      // Reset
+      for (int i = 0; i < getChildCount(); i++) {
+        View child = getChildAt(i);
+        ((MarginLayoutParams) child.getLayoutParams()).topMargin = originalTopMargins.get(child.getId());
+      }
+      // Layout
+      requestLayout();
+    }
+  }
+
+  @Override
+  protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
+    super.onLayout(changed, left, top, right, bottom);
+
+    if (displayCutout != null && Build.VERSION.SDK_INT >= Build.VERSION_CODES.P) {
+      updateTopMargins(displayCutout);
+      displayCutout = null;
+    }
+  }
+
+  @RequiresApi(api = Build.VERSION_CODES.P)
+  private void updateTopMargins(@NonNull DisplayCutout displayCutout) {
+    getLocationOnScreen(location);
+    int y = location[1];
+
+    for (int i = 0; i < getChildCount(); i++) {
+      View child = getChildAt(i);
+      child.getLocationOnScreen(location);
+
+      // Fix top margin
+      boolean intersected = false;
+      for (Rect notch : displayCutout.getBoundingRects()) {
+        rect.set(location[0], location[1], location[0] + child.getWidth(), location[1] + child.getHeight());
+        if (Rect.intersects(notch, rect)) {
+          intersected = true;
+          ((MarginLayoutParams) child.getLayoutParams()).topMargin = originalTopMargins.get(child.getId()) + (notch.bottom - y);
+          break;
+        }
+      }
+      if (!intersected) {
+        ((MarginLayoutParams) child.getLayoutParams()).topMargin = originalTopMargins.get(child.getId());
+      }
+
+      // Layout
+      requestLayout();
+    }
+  }
+}