Implement edge-to-edge keyboard padding with background

Re-implements dbecc26
without ugly transparency below the keyboard

Author: yawnoc

app/src/main/java/io/github/yawnoc/strokeinput/InputContainer.java

@@ -8,12 +8,18 @@
 package io.github.yawnoc.strokeinput;
 
 import android.content.Context;
+import android.graphics.Insets;
 import android.graphics.Typeface;
+import android.os.Build;
 import android.util.AttributeSet;
 import android.view.View;
+import android.view.ViewGroup;
 import android.view.ViewTreeObserver;
+import android.view.WindowInsets;
 import android.widget.FrameLayout;
 
+import androidx.core.view.WindowInsetsCompat;
+
 import java.util.List;
 
 /*
@@ -23,6 +29,7 @@
       - Stroke sequence bar
       - Candidates view
       - Keyboard view
+      - Bottom spacer (needed in API level 35+ due to edge-to-edge)
     2. Key preview plane (overlaid)
 */
 public class InputContainer
@@ -34,6 +41,23 @@ public class InputContainer
   private CandidatesView candidatesView;
   private CandidatesViewAdapter candidatesViewAdapter;
   private KeyboardView keyboardView;
+  private View bottomSpacer;
+
+  @Override
+  public WindowInsets onApplyWindowInsets(WindowInsets insets)
+  {
+    super.onApplyWindowInsets(insets);
+
+    if (Build.VERSION.SDK_INT >= 35) // bottom spacing for edge-to-edge
+    {
+      final Insets systemBars = insets.getInsets(WindowInsetsCompat.Type.systemBars());
+      ViewGroup.LayoutParams layoutParameters = bottomSpacer.getLayoutParams();
+      layoutParameters.height = systemBars.bottom;
+      bottomSpacer.setLayoutParams(layoutParameters);
+    }
+
+    return insets;
+  }
 
   public InputContainer(final Context context, final AttributeSet attributes)
   {
@@ -70,6 +94,11 @@ public void initialiseKeyboardView(
     keyboardView.setKeyboard(keyboard);
   }
 
+  public void initialiseBottomSpacer()
+  {
+    bottomSpacer = findViewById(R.id.bottom_spacer);
+  }
+
   public void setPopupRecessLayout(final boolean isFullscreen)
   {
     if (isFullscreen)

app/src/main/java/io/github/yawnoc/strokeinput/StrokeInputService.java

@@ -196,6 +196,7 @@ public View onCreateInputView()
     inputContainer.initialiseStrokeSequenceBar(this);
     inputContainer.initialiseCandidatesView(this);
     inputContainer.initialiseKeyboardView(this, loadSavedKeyboard());
+    inputContainer.initialiseBottomSpacer();
 
     return inputContainer;
   }

app/src/main/res/layout/input_container.xml

@@ -52,6 +52,12 @@
       android:layout_width="wrap_content"
       android:layout_height="wrap_content"
     />
+    <View
+      android:id="@+id/bottom_spacer"
+      android:layout_width="match_parent"
+      android:layout_height="0dp"
+      android:background="@android:color/black"
+    />
   </LinearLayout>
   <io.github.yawnoc.strokeinput.KeyPreviewPlane
     android:id="@+id/key_preview_plane"