Add swipe-to-delete gesture.

Change-Id: I992e59702f9dfff17da2f4464e48c9228d42b1b3

4 files changed, 140 insertions, 15 deletions

diff --git a/src/com/android/gallery3d/data/FilterDeleteSet.java b/src/com/android/gallery3d/data/FilterDeleteSet.java
new file mode 100644
index 000000000..fc94eb8e0
--- /dev/null
+++ b/src/com/android/gallery3d/data/FilterDeleteSet.java
@@ -0,0 +1,115 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.gallery3d.data;
+
+import java.util.ArrayList;
+
+// FilterDeleteSet filters a base MediaSet to remove a deletion item. The user
+// can use the following method to change the deletion item:
+//
+// void setDeletion(Path path, int index);
+//
+// If the path is null, there is no deletion item.
+public class FilterDeleteSet extends MediaSet implements ContentListener {
+    private static final String TAG = "FilterDeleteSet";
+
+    private final MediaSet mBaseSet;
+    private Path mDeletionPath;
+    private int mDeletionIndexHint;
+    private boolean mNewDeletionSettingPending = false;
+
+    // This is set to true or false in reload(), so we know if the given
+    // mDelectionPath is still in the mBaseSet, and if so we can adjust the
+    // index and items.
+    private boolean mDeletionInEffect;
+    private int mDeletionIndex;
+
+    public FilterDeleteSet(Path path, MediaSet baseSet) {
+        super(path, INVALID_DATA_VERSION);
+        mBaseSet = baseSet;
+        mBaseSet.addContentListener(this);
+    }
+
+    @Override
+    public String getName() {
+        return mBaseSet.getName();
+    }
+
+    @Override
+    public int getMediaItemCount() {
+        if (mDeletionInEffect) {
+            return mBaseSet.getMediaItemCount() - 1;
+        } else {
+            return mBaseSet.getMediaItemCount();
+        }
+    }
+
+    @Override
+    public ArrayList<MediaItem> getMediaItem(int start, int count) {
+        if (!mDeletionInEffect || mDeletionIndex >= start + count) {
+            return mBaseSet.getMediaItem(start, count);
+        }
+        if (mDeletionIndex < start) {
+            return mBaseSet.getMediaItem(start + 1, count);
+        }
+        ArrayList<MediaItem> base = mBaseSet.getMediaItem(start, count + 1);
+        base.remove(mDeletionIndex - start);
+        return base;
+    }
+
+    @Override
+    public long reload() {
+        boolean newData = mBaseSet.reload() > mDataVersion;
+        if (!newData && !mNewDeletionSettingPending) return mDataVersion;
+        mNewDeletionSettingPending = false;
+        mDeletionInEffect = false;
+        if (mDeletionPath != null) {
+            // See if mDeletionPath can be found in the MediaSet. We don't want
+            // to search the whole mBaseSet, so we just search a small window
+            // that is close the the index hint.
+            int n = mBaseSet.getMediaItemCount();
+            int from = Math.max(mDeletionIndexHint - 5, 0);
+            int to = Math.min(mDeletionIndexHint + 5, n);
+            ArrayList<MediaItem> items = mBaseSet.getMediaItem(from, to - from);
+            for (int i = 0; i < items.size(); i++) {
+                MediaItem item = items.get(i);
+                if (item != null && item.getPath() == mDeletionPath) {
+                    mDeletionInEffect = true;
+                    mDeletionIndex = i + from;
+                }
+            }
+            // We cannot find this path. Set it to null to avoid further search.
+            if (!mDeletionInEffect) {
+                mDeletionPath = null;
+            }
+        }
+        mDataVersion = nextVersionNumber();
+        return mDataVersion;
+    }
+
+    @Override
+    public void onContentDirty() {
+        notifyContentChanged();
+    }
+
+    public void setDeletion(Path path, int indexHint) {
+        mDeletionPath = path;
+        mDeletionIndexHint = indexHint;
+        mNewDeletionSettingPending = true;
+        notifyContentChanged();
+    }
+}
diff --git a/src/com/android/gallery3d/data/FilterSource.java b/src/com/android/gallery3d/data/FilterSource.java
index d1a04c995..b3e6ee356 100644
--- a/src/com/android/gallery3d/data/FilterSource.java
+++ b/src/com/android/gallery3d/data/FilterSource.java
@@ -21,6 +21,7 @@ import com.android.gallery3d.app.GalleryApp;
 class FilterSource extends MediaSource {
     private static final String TAG = "FilterSource";
     private static final int FILTER_BY_MEDIATYPE = 0;
+    private static final int FILTER_BY_DELETE = 1;
 
     private GalleryApp mApplication;
     private PathMatcher mMatcher;
@@ -30,21 +31,28 @@ class FilterSource extends MediaSource {
         mApplication = application;
         mMatcher = new PathMatcher();
         mMatcher.add("/filter/mediatype/*/*", FILTER_BY_MEDIATYPE);
+        mMatcher.add("/filter/delete/*", FILTER_BY_DELETE);
     }
 
-    // The name we accept is:
-    // /filter/mediatype/k/{set}
-    // where k is the media type we want.
+    // The name we accept are:
+    // /filter/mediatype/k/{set}    where k is the media type we want.
+    // /filter/delete/{set}
     @Override
     public MediaObject createMediaObject(Path path) {
         int matchType = mMatcher.match(path);
-        int mediaType = mMatcher.getIntVar(0);
-        String setsName = mMatcher.getVar(1);
         DataManager dataManager = mApplication.getDataManager();
-        MediaSet[] sets = dataManager.getMediaSetsFromString(setsName);
         switch (matchType) {
-            case FILTER_BY_MEDIATYPE:
-                return new FilterSet(path, dataManager, sets[0], mediaType);
+            case FILTER_BY_MEDIATYPE: {
+                int mediaType = mMatcher.getIntVar(0);
+                String setsName = mMatcher.getVar(1);
+                MediaSet[] sets = dataManager.getMediaSetsFromString(setsName);
+                return new FilterTypeSet(path, dataManager, sets[0], mediaType);
+            }
+            case FILTER_BY_DELETE: {
+                String setsName = mMatcher.getVar(0);
+                MediaSet[] sets = dataManager.getMediaSetsFromString(setsName);
+                return new FilterDeleteSet(path, sets[0]);
+            }
             default:
                 throw new RuntimeException("bad path: " + path);
         }
diff --git a/src/com/android/gallery3d/data/FilterSet.java b/src/com/android/gallery3d/data/FilterTypeSet.java
index 9cb7e02ef..1983a39f1 100644
--- a/src/com/android/gallery3d/data/FilterSet.java
+++ b/src/com/android/gallery3d/data/FilterTypeSet.java
@@ -18,12 +18,10 @@ package com.android.gallery3d.data;
 
 import java.util.ArrayList;
 
-// FilterSet filters a base MediaSet according to a condition. Currently the
-// condition is a matching media type. It can be extended to other conditions
-// if needed.
-public class FilterSet extends MediaSet implements ContentListener {
+// FilterTypeSet filters a base MediaSet according to a matching media type.
+public class FilterTypeSet extends MediaSet implements ContentListener {
     @SuppressWarnings("unused")
-    private static final String TAG = "FilterSet";
+    private static final String TAG = "FilterTypeSet";
 
     private final DataManager mDataManager;
     private final MediaSet mBaseSet;
@@ -31,7 +29,7 @@ public class FilterSet extends MediaSet implements ContentListener {
     private final ArrayList<Path> mPaths = new ArrayList<Path>();
     private final ArrayList<MediaSet> mAlbums = new ArrayList<MediaSet>();
 
-    public FilterSet(Path path, DataManager dataManager, MediaSet baseSet,
+    public FilterTypeSet(Path path, DataManager dataManager, MediaSet baseSet,
             int mediaType) {
         super(path, INVALID_DATA_VERSION);
         mDataManager = dataManager;
diff --git a/src/com/android/gallery3d/data/MtpSource.java b/src/com/android/gallery3d/data/MtpSource.java
index 683a40291..aaf50ad4c 100644
--- a/src/com/android/gallery3d/data/MtpSource.java
+++ b/src/com/android/gallery3d/data/MtpSource.java
@@ -18,7 +18,7 @@ package com.android.gallery3d.data;
 
 import com.android.gallery3d.app.GalleryApp;
 
-class MtpSource extends MediaSource {
+public class MtpSource extends MediaSource {
     private static final String TAG = "MtpSource";
 
     private static final int MTP_DEVICESET = 0;
@@ -68,4 +68,8 @@ class MtpSource extends MediaSource {
     public void resume() {
         mMtpContext.resume();
     }
+
+    public static boolean isMtpPath(String s) {
+        return s != null && Path.fromString(s).getPrefix().equals("mtp");
+    }
 }