Apply better coordinatorlayout animation and RTL support.

app/src/main/java/org/thoughtcrime/securesms/groups/ui/creategroup/GroupSettingsCoordinatorLayoutBehavior.java

@@ -0,0 +1,129 @@
+package org.thoughtcrime.securesms.groups.ui.creategroup;
+
+import android.content.Context;
+import android.graphics.Rect;
+import android.util.AttributeSet;
+import android.view.View;
+import android.view.animation.DecelerateInterpolator;
+import android.view.animation.Interpolator;
+import android.widget.TextView;
+
+import androidx.annotation.IdRes;
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.coordinatorlayout.widget.CoordinatorLayout;
+
+import com.google.android.material.appbar.AppBarLayout;
+
+import org.thoughtcrime.securesms.R;
+
+import java.lang.ref.WeakReference;
+
+public final class GroupSettingsCoordinatorLayoutBehavior extends CoordinatorLayout.Behavior<View> {
+
+  private static final Interpolator INTERPOLATOR = new DecelerateInterpolator();
+
+  private final ViewRef avatarTargetRef    = new ViewRef(R.id.avatar_target);
+  private final ViewRef groupNameRef       = new ViewRef(R.id.group_name);
+  private final ViewRef groupNameTargetRef = new ViewRef(R.id.group_name_target);
+  private final Rect    targetRect         = new Rect();
+  private final Rect    childRect          = new Rect();
+
+  public GroupSettingsCoordinatorLayoutBehavior(@NonNull Context context, @Nullable AttributeSet attrs) {
+  }
+
+  @Override
+  public boolean layoutDependsOn(@NonNull CoordinatorLayout parent, @NonNull View child, @NonNull View dependency) {
+    return dependency instanceof AppBarLayout;
+  }
+
+  @Override
+  public boolean onDependentViewChanged(@NonNull CoordinatorLayout parent, @NonNull View child, @NonNull View dependency) {
+    AppBarLayout appBarLayout = (AppBarLayout) dependency;
+    int          range        = appBarLayout.getTotalScrollRange();
+    float        factor       = INTERPOLATOR.getInterpolation(-appBarLayout.getY() / range);
+
+    updateAvatarPositionAndScale(parent, child, factor);
+    updateNamePosition(parent, factor);
+
+    return true;
+  }
+
+  private void updateAvatarPositionAndScale(@NonNull CoordinatorLayout parent, @NonNull View child, float factor) {
+    View target = avatarTargetRef.require(parent);
+
+    targetRect.set(target.getLeft(), target.getTop(), target.getRight(), target.getBottom());
+    childRect.set(child.getLeft(), child.getTop(), child.getRight(), child.getBottom());
+
+    float widthScale  = 1f - (1f - (targetRect.width() / (float) childRect.width())) * factor;
+    float heightScale = 1f - (1f - (targetRect.height() / (float) childRect.height())) * factor;
+
+    float superimposedLeft = childRect.left + (childRect.width() - targetRect.width()) / 2f;
+    float superimposedTop  = childRect.top + (childRect.height() - targetRect.height()) / 2f;
+
+    float xTranslation = (targetRect.left - superimposedLeft) * factor;
+    float yTranslation = (targetRect.top - superimposedTop) * factor;
+
+    child.setScaleX(widthScale);
+    child.setScaleY(heightScale);
+    child.setTranslationX(xTranslation);
+    child.setTranslationY(yTranslation);
+  }
+
+  private void updateNamePosition(@NonNull CoordinatorLayout parent, float factor) {
+    TextView child  = (TextView) groupNameRef.require(parent);
+    View     target = groupNameTargetRef.require(parent);
+
+    targetRect.set(target.getLeft(), target.getTop(), target.getRight(), target.getBottom());
+    childRect.set(child.getLeft(), child.getTop(), child.getRight(), child.getBottom());
+
+    if (child.getMaxWidth() != targetRect.width()) {
+      child.setMaxWidth(targetRect.width());
+    }
+
+    float deltaTop   = targetRect.top - childRect.top;
+    float deltaStart = getStart(parent, targetRect) - getStart(parent, childRect);
+
+    float yTranslation = deltaTop * factor;
+    float xTranslation = deltaStart * factor;
+
+    child.setTranslationY(yTranslation);
+    child.setTranslationX(xTranslation);
+  }
+
+  private static int getStart(@NonNull CoordinatorLayout parent, @NonNull Rect rect) {
+    return parent.getLayoutDirection() == View.LAYOUT_DIRECTION_LTR ? rect.left : rect.right;
+  }
+
+  private static final class ViewRef {
+
+    private WeakReference<View> ref = new WeakReference<>(null);
+
+    private final @IdRes int idRes;
+
+    private ViewRef(@IdRes int idRes) {
+      this.idRes = idRes;
+    }
+
+    private @NonNull View require(@NonNull View parent) {
+      View view = ref.get();
+
+      if (view == null) {
+        view = getChildOrThrow(parent, idRes);
+        ref  = new WeakReference<>(view);
+      }
+
+      return view;
+    }
+
+    private static @NonNull View getChildOrThrow(@NonNull View parent, @IdRes int id) {
+      View child = parent.findViewById(id);
+
+      if (child == null) {
+        throw new AssertionError("Can't find view with ID " + R.id.avatar_target);
+      } else {
+        return child;
+      }
+    }
+  }
+}

app/src/main/java/org/thoughtcrime/securesms/groups/ui/managegroup/ManageGroupFragment.java

@@ -64,6 +64,7 @@ public class ManageGroupFragment extends Fragment {
   private View                               pendingMembersRow;
   private TextView                           pendingMembersCount;
   private Toolbar                            toolbar;
+  private TextView                           groupName;
   private TextView                           memberCountUnderAvatar;
   private TextView                           memberCountAboveList;
   private AvatarImageView                    avatar;
@@ -115,6 +116,7 @@ public class ManageGroupFragment extends Fragment {
 
     avatar                      = view.findViewById(R.id.group_avatar);
     toolbar                     = view.findViewById(R.id.toolbar);
+    groupName                   = view.findViewById(R.id.group_name);
     memberCountUnderAvatar      = view.findViewById(R.id.member_count);
     memberCountAboveList        = view.findViewById(R.id.member_count_2);
     groupMemberList             = view.findViewById(R.id.group_members);
@@ -185,7 +187,7 @@ public class ManageGroupFragment extends Fragment {
     toolbar.inflateMenu(R.menu.manage_group_fragment);
 
     viewModel.getCanEditGroupAttributes().observe(getViewLifecycleOwner(), canEdit -> toolbar.getMenu().findItem(R.id.action_edit).setVisible(canEdit));
-    viewModel.getTitle().observe(getViewLifecycleOwner(), toolbar::setTitle);
+    viewModel.getTitle().observe(getViewLifecycleOwner(), groupName::setText);
     viewModel.getMemberCountSummary().observe(getViewLifecycleOwner(), memberCountUnderAvatar::setText);
     viewModel.getFullMemberCountSummary().observe(getViewLifecycleOwner(), memberCountAboveList::setText);
     viewModel.getGroupRecipient().observe(getViewLifecycleOwner(), groupRecipient -> {