Make zoom more smooth.

Originally startSmoothZoom and stopSmoothZoom were called
many times even while the zoom button is being pressed.
Now startSmoothZoom is only called once when the button is
pressed and stopSmoothZoom is called once when the button
is unpressed.

Change-Id: I88a7c5027e54a3b36759ded448530cfd310aa0aa

1 files changed, 37 insertions, 8 deletions

diff --git a/src/com/android/camera/ui/ZoomPicker.java b/src/com/android/camera/ui/ZoomPicker.java
index 98e18d7..6d31fe8 100644
--- a/src/com/android/camera/ui/ZoomPicker.java
+++ b/src/com/android/camera/ui/ZoomPicker.java
@@ -40,6 +40,7 @@ public class ZoomPicker extends LinearLayout {
     private TextView mZoomTextView;
     private int mZoomMax, mZoomIndex;
     private float[] mZoomRatios;
+    private boolean mSmoothZoomSupported;
     private OnZoomChangedListener mListener;
     private boolean mIncrement, mDecrement;
     private final StringBuilder mBuilder = new StringBuilder();
@@ -49,17 +50,30 @@ public class ZoomPicker extends LinearLayout {
     private Button mIncrementButton;
     private Button mDecrementButton;
 
+    // The state of zoom button.
+    public static final int ZOOM_IN = 0;
+    public static final int ZOOM_OUT = 1;
+    public static final int ZOOM_STOP = 2;
+
     private Handler mHandler;
     private final Runnable mRunnable = new Runnable() {
         public void run() {
             if (mIncrement) {
                 mIncrementButton.setBackgroundResource(R.drawable.button_zoom_in_longpressed_holo);
-                if (changeZoomIndex(mZoomIndex + 1)) {
+                if (mSmoothZoomSupported) {
+                    if (mZoomIndex != mZoomMax && mListener != null) {
+                        mListener.onZoomStateChanged(ZOOM_IN);
+                    }
+                } else if (changeZoomIndex(mZoomIndex + 1)) {
                     mHandler.postDelayed(this, 65);
                 }
             } else if (mDecrement) {
                 mDecrementButton.setBackgroundResource(R.drawable.button_zoom_out_longpressed_holo);
-                if (changeZoomIndex(mZoomIndex - 1)) {
+                if (mSmoothZoomSupported) {
+                    if (mZoomIndex != 0 && mListener != null) {
+                        mListener.onZoomStateChanged(ZOOM_OUT);
+                    }
+                } else if (changeZoomIndex(mZoomIndex - 1)) {
                     mHandler.postDelayed(this, 65);
                 }
             }
@@ -78,16 +92,21 @@ public class ZoomPicker extends LinearLayout {
 
         OnTouchListener incrementTouchListener = new OnTouchListener() {
             public boolean onTouch(View v, MotionEvent event) {
-                if (event.getAction() == MotionEvent.ACTION_DOWN) {
+                int action = event.getAction();
+                if (action == MotionEvent.ACTION_DOWN) {
                     if (!mIncrement && changeZoomIndex(mZoomIndex + 1)) {
                         mIncrement = true;
                         // Give bigger delay so users can tap to change only one
                         // zoom step.
                         mHandler.postDelayed(mRunnable, 300);
                     }
-                } else if (event.getAction() == MotionEvent.ACTION_UP) {
+                } else if (action == MotionEvent.ACTION_UP
+                        || action == MotionEvent.ACTION_CANCEL) {
                     mIncrementButton.setBackgroundResource(R.drawable.btn_zoom_in);
                     mIncrement = false;
+                    if (mSmoothZoomSupported) {
+                        if (mListener != null) mListener.onZoomStateChanged(ZOOM_STOP);
+                    }
                 }
                 return false;
             }
@@ -95,16 +114,21 @@ public class ZoomPicker extends LinearLayout {
 
         OnTouchListener decrementTouchListener = new OnTouchListener() {
             public boolean onTouch(View v, MotionEvent event) {
-                if (event.getAction() == MotionEvent.ACTION_DOWN) {
+                int action = event.getAction();
+                if (action == MotionEvent.ACTION_DOWN) {
                     if (!mDecrement && changeZoomIndex(mZoomIndex - 1)) {
                         mDecrement = true;
                         // Give bigger delay so users can tap to change only one
                         // zoom step.
                         mHandler.postDelayed(mRunnable, 300);
                     }
-                } else if (event.getAction() == MotionEvent.ACTION_UP) {
+                } else if (action == MotionEvent.ACTION_UP
+                        || action == MotionEvent.ACTION_CANCEL) {
                     mDecrementButton.setBackgroundResource(R.drawable.btn_zoom_out);
                     mDecrement = false;
+                    if (mSmoothZoomSupported) {
+                        if (mListener != null) mListener.onZoomStateChanged(ZOOM_STOP);
+                    }
                 }
                 return false;
             }
@@ -121,7 +145,8 @@ public class ZoomPicker extends LinearLayout {
     }
 
     public interface OnZoomChangedListener {
-        void onZoomChanged(int index);
+        void onZoomValueChanged(int index);  // only for immediate zoom
+        void onZoomStateChanged(int state);  // only for smooth zoom
     }
 
     public void setZoomRatios(float[] zoomRatios) {
@@ -138,11 +163,15 @@ public class ZoomPicker extends LinearLayout {
         updateView();
     }
 
+    public void setSmoothZoomSupported(boolean smoothZoomSupported) {
+        mSmoothZoomSupported = smoothZoomSupported;
+    }
+
     private boolean changeZoomIndex(int index) {
         if (index > mZoomMax || index < 0) return false;
         mZoomIndex = index;
         if (mListener != null) {
-            mListener.onZoomChanged(mZoomIndex);
+            mListener.onZoomValueChanged(mZoomIndex);
         }
         updateView();
         return true;