Merge branch '1582-restore-recycler-view-behaviour' into 'master'

Restore custom layout behaviour for handling snackbar

Closes #1582

See merge request briar/briar!1170

briar-android/src/main/java/org/briarproject/briar/android/view/DefaultBehavior.java

-package org.briarproject.briar.android.view;
-
-import android.content.Context;
-import android.support.design.widget.CoordinatorLayout.Behavior;
-import android.util.AttributeSet;
-import android.view.View;
-
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-@NotNullByDefault
-public class DefaultBehavior<V extends View> extends Behavior<V> {
-
-	public DefaultBehavior(Context context, AttributeSet attrs) {
-		super(context, attrs);
-	}
-}

briar-android/src/main/java/org/briarproject/briar/android/view/SnackbarAwareBehavior.java

+package org.briarproject.briar.android.view;
+
+import android.content.Context;
+import android.support.design.widget.CoordinatorLayout;
+import android.support.design.widget.CoordinatorLayout.Behavior;
+import android.support.design.widget.CoordinatorLayout.LayoutParams;
+import android.support.design.widget.Snackbar.SnackbarLayout;
+import android.util.AttributeSet;
+import android.view.View;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+/**
+ * This behavior makes room for a snackbar at the bottom of the screen. The
+ * proper solution is to use layout_dodgeInsetEdges="bottom", but when used on
+ * a scrollable view that results in the view being pushed under the app bar
+ * (see https://issuetracker.google.com/issues/116541304).
+ */
+@NotNullByDefault
+public class SnackbarAwareBehavior<V extends View> extends Behavior<V> {
+
+	public SnackbarAwareBehavior(Context context, AttributeSet attrs) {
+		super(context, attrs);
+	}
+
+	@Override
+	public boolean onDependentViewChanged(CoordinatorLayout parent,
+			V child, View snackbar) {
+		setMargin(child, snackbar.getHeight());
+		return true;
+	}
+
+	@Override
+	public void onDependentViewRemoved(CoordinatorLayout parent,
+			V child, View snackbar) {
+		setMargin(child, 0);
+	}
+
+	@Override
+	public boolean layoutDependsOn(CoordinatorLayout parent,
+			V child, View dependency) {
+		return dependency instanceof SnackbarLayout;
+	}
+
+	private void setMargin(V child, int margin) {
+		LayoutParams params = (LayoutParams) child.getLayoutParams();
+		params.setMargins(0, 0, 0, margin);
+		child.setLayoutParams(params);
+	}
+}

briar-android/src/main/res/layout/fragment_contact_list.xml

@@ -9,7 +9,7 @@
 		android:id="@+id/list"
 		android:layout_width="match_parent"
 		android:layout_height="match_parent"
-		app:layout_dodgeInsetEdges="bottom"
+		app:layout_behavior="org.briarproject.briar.android.view.SnackbarAwareBehavior"
 		app:scrollToEnd="false"/>
 
 	<io.github.kobakei.materialfabspeeddial.FabSpeedDial
@@ -22,7 +22,6 @@
 		app:fab_miniFabTextBackground="@color/briar_accent"
 		app:fab_miniFabTextColor="@android:color/white"
 		app:layout_anchorGravity="bottom|right|end"
-		app:layout_behavior="org.briarproject.briar.android.view.DefaultBehavior"
-		app:layout_dodgeInsetEdges="bottom"/>
+		app:layout_behavior="org.briarproject.briar.android.view.SnackbarAwareBehavior"/>
 
 </android.support.design.widget.CoordinatorLayout>