support for flinging in images

this is a bad attempt at getting the image viewer activity
to support swiping back/forward with your finger

2 files changed, 120 insertions, 4 deletions

diff --git a/src/org/linaro/connect/FlingListener.java b/src/org/linaro/connect/FlingListener.java
new file mode 100644
index 0000000..515060f
--- /dev/null
+++ b/src/org/linaro/connect/FlingListener.java
@@ -0,0 +1,89 @@
+package org.linaro.connect;
+
+import android.view.GestureDetector;
+import android.view.GestureDetector.OnDoubleTapListener;
+import android.view.GestureDetector.OnGestureListener;
+import android.view.MotionEvent;
+import android.view.View;
+import android.view.View.OnTouchListener;
+
+public class FlingListener implements OnGestureListener, OnDoubleTapListener {
+
+	private final FlingEvent mEvent;
+	private boolean mEnableForward = true;
+	private boolean mEnableBack = true;
+
+	public FlingListener(View v, FlingEvent fe) {
+		mEvent = fe;
+
+		final GestureDetector gd = new GestureDetector(this);
+		v.setOnTouchListener(new OnTouchListener() {
+			@Override
+			public boolean onTouch(View v, MotionEvent me) {
+				return gd.onTouchEvent(me);
+			}
+		});
+	}
+
+	public void enableForward(boolean enabled) {
+		mEnableForward = enabled;
+	}
+
+	public void enableBack(boolean enabled) {
+		mEnableBack = enabled;
+	}
+
+	@Override
+	public boolean onDown(MotionEvent e) {
+		return true;
+	}
+
+	@Override
+	public boolean onFling(MotionEvent e1, MotionEvent e2,
+			final float velocityX, final float velocityY) {
+		if(mEnableForward && velocityX < 0)
+			mEvent.onFlingForward();
+		else if( mEnableBack && velocityX > 0 )
+			mEvent.onFlingBack();
+		return true;
+	}
+
+	@Override
+	public boolean onDoubleTap(MotionEvent e) {
+		return true;
+	}
+
+	@Override
+	public void onLongPress(MotionEvent e) {
+	}
+
+	@Override
+	public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX,
+			float distanceY) {
+		return true;
+	}
+
+	@Override
+	public void onShowPress(MotionEvent e) {
+	}
+
+	@Override
+	public boolean onSingleTapUp(MotionEvent e) {
+		return false;
+	}
+
+	@Override
+	public boolean onDoubleTapEvent(MotionEvent e) {
+		return false;
+	}
+
+	@Override
+	public boolean onSingleTapConfirmed(MotionEvent e) {
+		return false;
+	}
+
+	public interface FlingEvent {
+		void onFlingForward();
+		void onFlingBack();
+	}
+}
diff --git a/src/org/linaro/connect/ImageViewActivity.java b/src/org/linaro/connect/ImageViewActivity.java
index f6b3721..94411eb 100644
--- a/src/org/linaro/connect/ImageViewActivity.java
+++ b/src/org/linaro/connect/ImageViewActivity.java
@@ -3,6 +3,7 @@ package org.linaro.connect;
 import org.json.JSONArray;
 import org.json.JSONException;
 import org.json.JSONObject;
+import org.linaro.connect.FlingListener.FlingEvent;
 
 import android.app.Activity;
 import android.content.Intent;
@@ -25,6 +26,8 @@ public class ImageViewActivity extends Activity {
 	private ImageButton mBack;
 	private ImageButton mForward;
 
+	private FlingListener mFlingListener;
+
 	@Override
 	protected void onCreate(Bundle savedInstanceState) {
 		requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS);
@@ -51,6 +54,8 @@ public class ImageViewActivity extends Activity {
 			}
 		});
 
+		setFlingListener(findViewById(R.id.image_view_id));
+
 		Intent i = getIntent();
 		String json = i.getStringExtra("json");
 		JSONObject jso = JSONUtils.toJSON(json);
@@ -64,6 +69,20 @@ public class ImageViewActivity extends Activity {
 		}
 	}
 
+	private void setFlingListener(View v) {
+		mFlingListener = new FlingListener(v, new FlingEvent() {
+			@Override
+			public void onFlingForward() {
+				setSelected(mSelected+1);
+			}
+
+			@Override
+			public void onFlingBack() {
+				setSelected(mSelected-1);
+			}
+		});
+	}
+
 	private void setSelected(int pos) {
 		disableNavigation();
 
@@ -103,6 +122,8 @@ public class ImageViewActivity extends Activity {
 		mForward.setEnabled(false);
 		mBack.setVisibility(View.INVISIBLE);
 		mForward.setVisibility(View.INVISIBLE);
+		mFlingListener.enableForward(false);
+		mFlingListener.enableBack(false);
 	}
 
 	private void enableNavigation() {
@@ -110,15 +131,21 @@ public class ImageViewActivity extends Activity {
 		mBack.setEnabled(true);
 		mForward.setEnabled(true);
 
-		if( mSelected < 1 )
+		if( mSelected < 1 ) {
 			mBack.setVisibility(View.INVISIBLE);
-		else
+			mFlingListener.enableBack(false);
+		} else {
 			mBack.setVisibility(View.VISIBLE);
+			mFlingListener.enableBack(true);
+		}
 
-		if( mSelected >= getNumImages()-1 )
+		if( mSelected >= getNumImages()-1 ) {
 			mForward.setVisibility(View.INVISIBLE);
-		else
+			mFlingListener.enableForward(false);
+		} else {
 			mForward.setVisibility(View.VISIBLE);
+			mFlingListener.enableForward(true);
+		}
 	}
 
 	private class DownloadTask extends AsyncTask<JSONImageItem, Void, Drawable> {