| /* |
| * Copyright (C) 2008 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.camera; |
| |
| import android.content.Context; |
| import android.util.AttributeSet; |
| import android.view.View; |
| import android.widget.ImageView; |
| |
| /** |
| * A button designed to be used for the on-screen shutter button. |
| * It's currently an {@code ImageView} that can call a delegate when the |
| * pressed state changes. |
| */ |
| public class ShutterButton extends ImageView { |
| /** |
| * A callback to be invoked when a ShutterButton's pressed state changes. |
| */ |
| public interface OnShutterButtonListener { |
| /** |
| * Called when a ShutterButton has been pressed. |
| * |
| * @param pressed The ShutterButton that was pressed. |
| */ |
| void onShutterButtonFocus(boolean pressed); |
| void onShutterButtonClick(); |
| } |
| |
| private OnShutterButtonListener mListener; |
| private boolean mOldPressed; |
| |
| public ShutterButton(Context context, AttributeSet attrs) { |
| super(context, attrs); |
| } |
| |
| public void setOnShutterButtonListener(OnShutterButtonListener listener) { |
| mListener = listener; |
| } |
| |
| /** |
| * Hook into the drawable state changing to get changes to isPressed -- the |
| * onPressed listener doesn't always get called when the pressed state |
| * changes. |
| */ |
| @Override |
| protected void drawableStateChanged() { |
| super.drawableStateChanged(); |
| final boolean pressed = isPressed(); |
| if (pressed != mOldPressed) { |
| if (!pressed) { |
| // When pressing the physical camera button the sequence of |
| // events is: |
| // focus pressed, optional camera pressed, focus released. |
| // We want to emulate this sequence of events with the shutter |
| // button. When clicking using a trackball button, the view |
| // system changes the the drawable state before posting click |
| // notification, so the sequence of events is: |
| // pressed(true), optional click, pressed(false) |
| // When clicking using touch events, the view system changes the |
| // drawable state after posting click notification, so the |
| // sequence of events is: |
| // pressed(true), pressed(false), optional click |
| // Since we're emulating the physical camera button, we want to |
| // have the same order of events. So we want the optional click |
| // callback to be delivered before the pressed(false) callback. |
| // |
| // To do this, we delay the posting of the pressed(false) event |
| // slightly by pushing it on the event queue. This moves it |
| // after the optional click notification, so our client always |
| // sees events in this sequence: |
| // pressed(true), optional click, pressed(false) |
| post(new Runnable() { |
| public void run() { |
| callShutterButtonFocus(pressed); |
| } |
| }); |
| } else { |
| callShutterButtonFocus(pressed); |
| } |
| mOldPressed = pressed; |
| } |
| } |
| |
| private void callShutterButtonFocus(boolean pressed) { |
| if (mListener != null) { |
| mListener.onShutterButtonFocus(pressed); |
| } |
| } |
| |
| @Override |
| public boolean performClick() { |
| boolean result = super.performClick(); |
| if (mListener != null) { |
| mListener.onShutterButtonClick(); |
| } |
| return result; |
| } |
| } |