Issue#344 Snackbar added for user awareness resolved

app/src/main/java/com/zulip/android/activities/MessageListFragment.java

@@ -8,6 +8,10 @@
 import android.content.DialogInterface;
 import android.os.Build;
 import android.os.Bundle;
+import android.support.annotation.Nullable;
+import android.support.design.widget.CoordinatorLayout;
+import android.support.design.widget.FloatingActionButton;
+import android.support.design.widget.Snackbar;
 import android.support.v4.app.Fragment;
 import android.support.v7.app.AlertDialog;
 import android.support.v7.app.AppCompatActivity;
@@ -46,6 +50,7 @@
 import com.zulip.android.util.Constants;
 import com.zulip.android.util.MessageListener;
 import com.zulip.android.util.MutedTopics;
+import com.zulip.android.util.ShrinkBehaviorOfFab;
 import com.zulip.android.util.ZLog;
 import com.zulip.android.viewholders.HeaderSpaceItemDecoration;
 
@@ -86,6 +91,7 @@ public class MessageListFragment extends Fragment implements MessageListener {
     private boolean paused = false;
     private boolean initialized = false;
     private List<Message> messageList;
+    private Snackbar snackbar;
 
     public MessageListFragment() {
         app = ZulipApp.get();
@@ -182,6 +188,17 @@ public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
         return view;
     }
 
+    @Override
+    public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
+        super.onViewCreated(view, savedInstanceState);
+        CoordinatorLayout coordinatorLayout = (CoordinatorLayout) getActivity().findViewById(R.id.coordinatorLayout);
+        snackbar = Snackbar.make(coordinatorLayout, R.string.no_new_messages, Snackbar.LENGTH_SHORT)
+                .setDuration(1000);
+        FloatingActionButton floatingActionButton = (FloatingActionButton) coordinatorLayout.findViewById(R.id.fab);
+        CoordinatorLayout.LayoutParams params = (CoordinatorLayout.LayoutParams) floatingActionButton.getLayoutParams();
+        params.setBehavior(new ShrinkBehaviorOfFab());
+    }
+
     @Override
     public void onAttach(Activity activity) {
         super.onAttach(activity);
@@ -569,6 +586,10 @@ public void onMessages(Message[] messages, LoadPosition pos,
         if (!initialized) {
             return;
         }
+
+        if (loadedToBottom){
+            snackbar.show();
+        }
         Log.i("onMessages", "Adding " + messages.length + " messages at " + pos);
         int topPosBefore = linearLayoutManager.findFirstVisibleItemPosition();
         int addedCount = 0;

app/src/main/java/com/zulip/android/util/ShrinkBehaviorOfFab.java

@@ -0,0 +1,160 @@
+package com.zulip.android.util;
+
+import android.animation.Animator;
+import android.annotation.SuppressLint;
+import android.content.Context;
+import android.support.design.widget.AppBarLayout;
+import android.support.design.widget.CoordinatorLayout;
+import android.support.design.widget.FloatingActionButton;
+import android.support.design.widget.Snackbar;
+import android.support.v4.view.ViewCompat;
+import android.support.v4.view.animation.FastOutSlowInInterpolator;
+import android.support.v7.widget.LinearLayoutManager;
+import android.util.AttributeSet;
+import android.view.View;
+import android.view.ViewPropertyAnimator;
+import android.view.animation.Interpolator;
+import android.widget.LinearLayout;
+
+import com.zulip.android.R;
+import com.zulip.android.activities.RecyclerMessageAdapter;
+
+import java.util.List;
+
+public class ShrinkBehaviorOfFab extends CoordinatorLayout.Behavior<FloatingActionButton> {
+
+    private static final Interpolator FAST_OUT_SLOW_IN_INTERPOLATOR = new FastOutSlowInInterpolator();
+    private static float toolbarHeight;
+    private int changeInYDir;
+    private boolean mIsShowing;
+    private boolean isViewHidden;
+    private View chatBox;
+    private LinearLayoutManager linearLayoutManager;
+    private RecyclerMessageAdapter adapter;
+
+    public ShrinkBehaviorOfFab(){
+    }
+
+    public ShrinkBehaviorOfFab(Context context, AttributeSet attrs) {
+        super(context, attrs);
+    }
+
+    @Override
+    public boolean layoutDependsOn(CoordinatorLayout parent, FloatingActionButton child, View dependency) {
+        return dependency instanceof Snackbar.SnackbarLayout;
+    }
+
+    private float getFabTranslationYForSnackbar(CoordinatorLayout parent,
+                                                FloatingActionButton fab) {
+        float minOffset = 0;
+        final List<View> dependencies = parent.getDependencies(fab);
+        for (int i = 0, z = dependencies.size(); i < z; i++) {
+            final View view = dependencies.get(i);
+            if (view instanceof Snackbar.SnackbarLayout && parent.doViewsOverlap(fab, view)) {
+                minOffset = Math.min(minOffset,
+                        ViewCompat.getTranslationY(view) - view.getHeight());
+            }
+        }
+
+        return minOffset;
+    }
+
+    @Override
+    public boolean onDependentViewChanged(CoordinatorLayout parent, FloatingActionButton child, View dependency) {
+        float translationY = getFabTranslationYForSnackbar(parent, child);
+        float percentComplete = -translationY / dependency.getHeight();
+        float scaleFactor = 1 - percentComplete;
+
+        child.setScaleX(scaleFactor);
+        child.setScaleY(scaleFactor);
+        return false;
+    }
+
+    @Override
+    public boolean onStartNestedScroll(CoordinatorLayout coordinatorLayout, FloatingActionButton child, View directTargetChild, View target, int nestedScrollAxes) {
+        return true;
+    }
+
+    @Override
+    public void onNestedScroll(CoordinatorLayout coordinatorLayout, FloatingActionButton child, View target, int dxConsumed, int dyConsumed, int dxUnconsumed, int dyUnconsumed) {
+        super.onNestedScroll(coordinatorLayout, child, target, dxConsumed, dyConsumed, dxUnconsumed, dyUnconsumed);
+        if (dyConsumed > 0 && child.getVisibility() == View.VISIBLE) {
+            hideView(child);
+        } else if (dyConsumed < 0 && child.getVisibility() != View.VISIBLE) {
+            showView(child);
+        }
+    }
+
+    @SuppressLint("NewApi")
+    private void hideView(final View view) {
+        isViewHidden = true;
+        int y = view.getHeight();
+        ;
+        if (view instanceof AppBarLayout) {
+            y = -1 * view.getHeight();
+        } else if (view instanceof LinearLayout) {
+            y = 0;
+        }
+        ViewPropertyAnimator animator = view.animate()
+                .translationY(y)
+                .setInterpolator(FAST_OUT_SLOW_IN_INTERPOLATOR)
+                .setDuration(200);
+
+        animator.setListener(new Animator.AnimatorListener() {
+            @Override
+            public void onAnimationStart(Animator animator) {
+            }
+
+            @Override
+            public void onAnimationEnd(Animator animator) {
+                isViewHidden = false;
+                view.setVisibility(View.GONE);
+            }
+
+            @Override
+            public void onAnimationCancel(Animator animator) {
+                isViewHidden = false;
+                if (!mIsShowing)
+                    showView(view);
+            }
+
+            @Override
+            public void onAnimationRepeat(Animator animator) {
+            }
+        });
+        animator.start();
+    }
+
+    @SuppressLint("NewApi")
+    public void showView(final View view) {
+        mIsShowing = true;
+        ViewPropertyAnimator animator = view.animate()
+                .translationY((view.getId() == R.id.appBarLayout || view instanceof FloatingActionButton) ? 0 : toolbarHeight)
+                .setInterpolator(FAST_OUT_SLOW_IN_INTERPOLATOR)
+                .setDuration(200);
+
+        animator.setListener(new Animator.AnimatorListener() {
+            @Override
+            public void onAnimationStart(Animator animator) {
+                view.setVisibility(View.VISIBLE);
+            }
+
+            @Override
+            public void onAnimationEnd(Animator animator) {
+                mIsShowing = false;
+            }
+
+            @Override
+            public void onAnimationCancel(Animator animator) {
+                mIsShowing = false;
+                if (!isViewHidden)
+                    hideView(view);
+            }
+
+            @Override
+            public void onAnimationRepeat(Animator animator) {
+            }
+        });
+        animator.start();
+    }
+}

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

@@ -52,7 +52,7 @@
             android:src="@drawable/ic_mode_edit_24dp"
             app:backgroundTint="@color/colorPrimary"
             app:borderWidth="0dp"
-            app:layout_behavior="com.zulip.android.util.RemoveViewsOnScroll" />
+            app:layout_behavior="com.zulip.android.util.ShrinkBehaviorOfFab" />
     </android.support.design.widget.CoordinatorLayout>
 
     <android.support.design.widget.NavigationView

app/src/main/res/values/strings.xml

@@ -156,4 +156,5 @@
     <string name="copy_message_fetch">Copying message to clipboard</string>
     <string name="copy_failed">Copying to clipboard failed</string>
     <string name="try_again_error_msg">Something went wrong, try again</string>
+    <string name="no_new_messages">No new messages</string>
 </resources>