1 files changed, 107 insertions, 0 deletions
diff --git a/src/com/android/browser/KeyTracker.java b/src/com/android/browser/KeyTracker.java
new file mode 100644
index 00000000..344e4f85
--- /dev/null
+++ b/src/com/android/browser/KeyTracker.java
@@ -0,0 +1,107 @@
+/*
+ * Copyright (C) 2006 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.browser;
+
+import android.view.KeyEvent;
+import android.view.ViewConfiguration;
+
+class KeyTracker {
+
+    public enum Stage {
+        DOWN,           //!< the key has just been pressed
+        SHORT_REPEAT,   //!< repeated key, but duration is under the long-press threshold
+        LONG_REPEAT,    //!< repeated key, but duration is over the long-press threshold
+        UP              //!< the key is being released
+    }
+    
+    public enum State {
+        KEEP_TRACKING,  //!< return this to continue to track the key
+        DONE_TRACKING,  //!< return this if you handled the key, but need not track it anymore
+        NOT_TRACKING    //!< return this if you will not handle this key
+    }
+    
+    public interface OnKeyTracker {
+
+        /** Called whenever there is a key event [down, short/long repeat, up]
+            @param keyCode  The current keyCode (see KeyEvent class)
+            @param msg      The message associated with the keyCode
+            @maram stage    The state the key press is in [down, short/long repeat, up]
+            @param duration The number of milliseconds since this key was initially pressed
+            @return your state after seeing the key. If you return DONE_TRACKING or NOT_TRACKING,
+                    you will not be called again for the lifetime of this key event.
+        */
+        public State onKeyTracker(int keyCode, KeyEvent event, Stage stage, int duration);
+    }
+    
+    public KeyTracker(OnKeyTracker tracker) {
+        mTracker = tracker;
+    }
+    
+    public boolean doKeyDown(int keyCode, KeyEvent event) {
+        long now = System.currentTimeMillis();
+        Stage stage = null;
+
+        // check if its a new/different key
+        if (mKeyCode != keyCode || event.getRepeatCount() == 0) {
+            mKeyCode = keyCode;
+            mStartMS = now;
+            stage = Stage.DOWN;
+        }
+        else if (mState == State.KEEP_TRACKING) {
+            stage = (now - mStartMS) >= LONG_PRESS_DURATION_MS ? Stage.LONG_REPEAT : Stage.SHORT_REPEAT;
+        }
+
+        if (stage != null) {
+            mEvent = event;        
+            callTracker(stage, now);
+        }
+
+        return mState != State.NOT_TRACKING;
+    }
+    
+    public boolean doKeyUp(int keyCode, KeyEvent event) {
+        boolean handled = false;
+
+        if (mState == State.KEEP_TRACKING && mKeyCode == keyCode) {
+            mEvent = event;
+            callTracker(Stage.UP, System.currentTimeMillis());
+            handled = mState != State.NOT_TRACKING;
+        }
+        mKeyCode = NOT_A_KEYCODE;
+        return handled;
+    }
+    
+    private void callTracker(Stage stage, long now) {
+        mState = mTracker.onKeyTracker(mKeyCode, mEvent, stage, (int)(now - mStartMS));
+    }
+    
+    private void dump() {
+        System.out.println(" key=" + mKeyCode + " dur=" + (System.currentTimeMillis() - mStartMS) +
+                            " state=" + mState);
+    }
+
+    private int             mKeyCode = NOT_A_KEYCODE;
+    private KeyEvent        mEvent;
+    private long            mStartMS;
+    private State           mState;
+    private OnKeyTracker    mTracker;
+
+    private static final int LONG_PRESS_DURATION_MS = 
+            ViewConfiguration.getLongPressTimeout();
+    private static final int NOT_A_KEYCODE = -123456;
+}
+