Merge pull request #1115 from ShridharGoel/swipe-down

Swipe down on toolbar to open tabs switcher

app/src/main/java/org/kiwix/kiwixmobile/main/MainActivity.java

@@ -20,6 +20,7 @@
 package org.kiwix.kiwixmobile.main;
 
 import android.Manifest;
+import android.annotation.SuppressLint;
 import android.app.Activity;
 import android.appwidget.AppWidgetManager;
 import android.content.ActivityNotFoundException;
@@ -321,6 +322,7 @@ public class MainActivity extends BaseActivity implements WebViewCallback,
     }
   }
 
+  @SuppressLint("ClickableViewAccessibility")
   @Override
   public void onCreate(Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);
@@ -333,6 +335,13 @@ public class MainActivity extends BaseActivity implements WebViewCallback,
     setSupportActionBar(toolbar);
     actionBar = getSupportActionBar();
 
+    toolbar.setOnTouchListener(new OnSwipeTouchListener(this) {
+
+      public void onSwipeBottom() {
+        showTabSwitcher();
+      }
+    });
+
     tableDrawerRight =
         tableDrawerRightContainer.getHeaderView(0).findViewById(R.id.right_drawer_list);
 

app/src/main/java/org/kiwix/kiwixmobile/main/OnSwipeTouchListener.java

@@ -0,0 +1,70 @@
+package org.kiwix.kiwixmobile.main;
+
+import android.content.Context;
+import android.view.GestureDetector;
+import android.view.MotionEvent;
+import android.view.View;
+
+public class OnSwipeTouchListener implements View.OnTouchListener {
+  private final GestureDetector gestureDetector;
+
+  public OnSwipeTouchListener(Context ctx) {
+    gestureDetector = new GestureDetector(ctx, new GestureListener());
+  }
+
+  @Override
+  public boolean onTouch(View v, MotionEvent event) {
+    return gestureDetector.onTouchEvent(event);
+  }
+
+  private final class GestureListener extends GestureDetector.SimpleOnGestureListener {
+    private static final int SWIPE_THRESHOLD = 100;
+    private static final int SWIPE_VELOCITY_THRESHOLD = 100;
+
+    @Override
+    public boolean onDown(MotionEvent e) {
+      return true;
+    }
+
+    @Override
+    public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
+      boolean result = false;
+      try {
+        float diffY = e2.getY() - e1.getY();
+        float diffX = e2.getX() - e1.getX();
+        if (Math.abs(diffX) > Math.abs(diffY)) {
+          if (Math.abs(diffX) > SWIPE_THRESHOLD && Math.abs(velocityX) > SWIPE_VELOCITY_THRESHOLD) {
+            if (diffX > 0) {
+              onSwipeRight();
+            } else {
+              onSwipeLeft();
+            }
+            result = true;
+          }
+        } else if (Math.abs(diffY) > SWIPE_THRESHOLD && Math.abs(velocityY) > SWIPE_VELOCITY_THRESHOLD) {
+          if (diffY > 0) {
+            onSwipeBottom();
+          } else {
+            onSwipeTop();
+          }
+          result = true;
+        }
+      } catch (Exception exception) {
+        exception.printStackTrace();
+      }
+      return result;
+    }
+  }
+
+  public void onSwipeRight() {
+  }
+
+  public void onSwipeLeft() {
+  }
+
+  public void onSwipeTop() {
+  }
+
+  public void onSwipeBottom() {
+  }
+}