Listeners

zoomage/src/main/java/com/jsibbold/zoomage/OnGestureListener.java

@@ -0,0 +1,50 @@
+package com.jsibbold.zoomage;
+
+import android.view.GestureDetector;
+import android.view.MotionEvent;
+
+/**
+ * Default implementation of GestureListener for {@link ZoomageView}.
+ * If you want to change it in {@link ZoomageView} - override method {@link ZoomageView#getOnGestureListener()}
+ * and provide your own implementation
+ */
+public class OnGestureListener extends GestureDetector.SimpleOnGestureListener {
+
+    private final ZoomageView view;
+
+    public OnGestureListener(ZoomageView view) {
+        this.view = view;
+    }
+
+    @Override
+    public boolean onDoubleTapEvent(MotionEvent e) {
+        if (view != null && e.getAction() == MotionEvent.ACTION_UP) {
+            view.setDoubleTapDetected(true);
+        }
+        notifySingleTapDetection(true);
+        return false;
+    }
+
+    @Override
+    public boolean onSingleTapUp(MotionEvent e) {
+        notifySingleTapDetection(true);
+        return false;
+    }
+
+    private void notifySingleTapDetection(boolean detected) {
+        if (view != null) {
+            view.setSingleTapDetected(detected);
+        }
+    }
+
+    @Override
+    public boolean onSingleTapConfirmed(MotionEvent e) {
+        notifySingleTapDetection(false);
+        return false;
+    }
+
+    @Override
+    public boolean onDown(MotionEvent e) {
+        return true;
+    }
+}

zoomage/src/main/java/com/jsibbold/zoomage/OnScaleChangeListener.java

@@ -0,0 +1,8 @@
+package com.jsibbold.zoomage;
+
+/**
+ * Listener, that provides updates about scale changes in {@link ZoomageView}
+ */
+public interface OnScaleChangeListener {
+    void onScaleChanged(float newScale);
+}

zoomage/src/main/java/com/jsibbold/zoomage/ZoomageView.java

@@ -89,6 +89,7 @@ public class ZoomageView extends AppCompatImageView implements OnScaleGestureLis
     private GestureDetector gestureDetector;
     private boolean doubleTapDetected = false;
     private boolean singleTapDetected = false;
+    private OnScaleChangeListener onScaleChangeListener;
 
     public ZoomageView(Context context) {
         super(context);
@@ -107,7 +108,7 @@ public ZoomageView(Context context, AttributeSet attrs, int defStyle) {
 
     private void init(Context context, AttributeSet attrs) {
         scaleDetector = new ScaleGestureDetector(context, this);
-        gestureDetector = new GestureDetector(context, gestureListener);
+        gestureDetector = new GestureDetector(context, getOnGestureListener());
         ScaleGestureDetectorCompat.setQuickScaleEnabled(scaleDetector, false);
         startScaleType = getScaleType();
 
@@ -129,6 +130,10 @@ private void init(Context context, AttributeSet attrs) {
         values.recycle();
     }
 
+    protected GestureDetector.OnGestureListener getOnGestureListener() {
+        return new OnGestureListener(this);
+    }
+
     private void verifyScaleRange() {
         if (minScale >= maxScale) {
             throw new IllegalStateException("minScale must be less than maxScale");
@@ -500,6 +505,7 @@ public boolean onTouchEvent(MotionEvent event) {
                     if (allowZoom(event)) {
                         matrix.postScale(scaleBy, scaleBy, focusx, focusy);
                         currentScaleFactor = matrixValues[Matrix.MSCALE_X] / startValues[Matrix.MSCALE_X];
+                        notifyScaleChangeListener(currentScaleFactor);
                     }
 
                     setImageMatrix(matrix);
@@ -657,6 +663,10 @@ public void onAnimationUpdate(ValueAnimator animation) {
             @Override
             public void onAnimationEnd(Animator animation) {
                 setImageMatrix(targetMatrix);
+                if (currentScaleFactor < 1F) {
+                    currentScaleFactor = 1F;
+                }
+                notifyScaleChangeListener(currentScaleFactor);
             }
         });
 
@@ -868,35 +878,27 @@ public void onScaleEnd(ScaleGestureDetector detector) {
         scaleBy = 1f;
     }
 
-    private final GestureDetector.OnGestureListener gestureListener = new GestureDetector.SimpleOnGestureListener() {
-        @Override
-        public boolean onDoubleTapEvent(MotionEvent e) {
-            if (e.getAction() == MotionEvent.ACTION_UP) {
-                doubleTapDetected = true;
-            }
+    public OnScaleChangeListener getOnScaleChangeListener() {
+        return onScaleChangeListener;
+    }
 
-            singleTapDetected = false;
+    public void setOnScaleChangeListener(OnScaleChangeListener onScaleChangeListener) {
+        this.onScaleChangeListener = onScaleChangeListener;
+    }
 
-            return false;
-        }
-
-        @Override
-        public boolean onSingleTapUp(MotionEvent e) {
-            singleTapDetected = true;
-            return false;
+    private void notifyScaleChangeListener(float newScale) {
+        if (onScaleChangeListener != null) {
+            onScaleChangeListener.onScaleChanged(newScale);
         }
+    }
 
-        @Override
-        public boolean onSingleTapConfirmed(MotionEvent e) {
-            singleTapDetected = false;
-            return false;
-        }
+    void setDoubleTapDetected(boolean detected) {
+        doubleTapDetected = detected;
+    }
 
-        @Override
-        public boolean onDown(MotionEvent e) {
-            return true;
-        }
-    };
+    void setSingleTapDetected(boolean detected) {
+        singleTapDetected = detected;
+    }
 
     private class SimpleAnimatorListener implements Animator.AnimatorListener {
         @Override