android.widget.ZoomButtonsController Maven / Gradle / Ivy
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/*
* 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 android.widget;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.graphics.PixelFormat;
import android.graphics.Rect;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
import android.view.Gravity;
import android.view.KeyEvent;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewConfiguration;
import android.view.ViewGroup;
import android.view.ViewParent;
import android.view.ViewRootImpl;
import android.view.WindowManager;
import android.view.View.OnClickListener;
import android.view.WindowManager.LayoutParams;
/*
* Implementation notes:
* - The zoom controls are displayed in their own window.
* (Easier for the client and better performance)
* - This window is never touchable, and by default is not focusable.
* Its rect is quite big (fills horizontally) but has empty space between the
* edges and center. Touches there should be given to the owner. Instead of
* having the window touchable and dispatching these empty touch events to the
* owner, we set the window to not touchable and steal events from owner
* via onTouchListener.
* - To make the buttons clickable, it attaches an OnTouchListener to the owner
* view and does the hit detection locally (attaches when visible, detaches when invisible).
* - When it is focusable, it forwards uninteresting events to the owner view's
* view hierarchy.
*/
/**
* The {@link ZoomButtonsController} handles showing and hiding the zoom
* controls and positioning it relative to an owner view. It also gives the
* client access to the zoom controls container, allowing for additional
* accessory buttons to be shown in the zoom controls window.
*
* Typically, clients should call {@link #setVisible(boolean) setVisible(true)}
* on a touch down or move (no need to call {@link #setVisible(boolean)
* setVisible(false)} since it will time out on its own). Also, whenever the
* owner cannot be zoomed further, the client should update
* {@link #setZoomInEnabled(boolean)} and {@link #setZoomOutEnabled(boolean)}.
*
* If you are using this with a custom View, please call
* {@link #setVisible(boolean) setVisible(false)} from
* {@link View#onDetachedFromWindow} and from {@link View#onVisibilityChanged}
* when visibility != View.VISIBLE.
*
*/
public class ZoomButtonsController implements View.OnTouchListener {
private static final String TAG = "ZoomButtonsController";
private static final int ZOOM_CONTROLS_TIMEOUT =
(int) ViewConfiguration.getZoomControlsTimeout();
private static final int ZOOM_CONTROLS_TOUCH_PADDING = 20;
private int mTouchPaddingScaledSq;
private final Context mContext;
private final WindowManager mWindowManager;
private boolean mAutoDismissControls = true;
/**
* The view that is being zoomed by this zoom controller.
*/
private final View mOwnerView;
/**
* The location of the owner view on the screen. This is recalculated
* each time the zoom controller is shown.
*/
private final int[] mOwnerViewRawLocation = new int[2];
/**
* The container that is added as a window.
*/
private final FrameLayout mContainer;
private LayoutParams mContainerLayoutParams;
private final int[] mContainerRawLocation = new int[2];
private ZoomControls mControls;
/**
* The view (or null) that should receive touch events. This will get set if
* the touch down hits the container. It will be reset on the touch up.
*/
private View mTouchTargetView;
/**
* The {@link #mTouchTargetView}'s location in window, set on touch down.
*/
private final int[] mTouchTargetWindowLocation = new int[2];
/**
* If the zoom controller is dismissed but the user is still in a touch
* interaction, we set this to true. This will ignore all touch events until
* up/cancel, and then set the owner's touch listener to null.
*
* Otherwise, the owner view would get mismatched events (i.e., touch move
* even though it never got the touch down.)
*/
private boolean mReleaseTouchListenerOnUp;
/** Whether the container has been added to the window manager. */
private boolean mIsVisible;
private final Rect mTempRect = new Rect();
private final int[] mTempIntArray = new int[2];
private OnZoomListener mCallback;
/**
* When showing the zoom, we add the view as a new window. However, there is
* logic that needs to know the size of the zoom which is determined after
* it's laid out. Therefore, we must post this logic onto the UI thread so
* it will be exceuted AFTER the layout. This is the logic.
*/
private Runnable mPostedVisibleInitializer;
private final IntentFilter mConfigurationChangedFilter =
new IntentFilter(Intent.ACTION_CONFIGURATION_CHANGED);
/**
* Needed to reposition the zoom controls after configuration changes.
*/
private final BroadcastReceiver mConfigurationChangedReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
if (!mIsVisible) return;
mHandler.removeMessages(MSG_POST_CONFIGURATION_CHANGED);
mHandler.sendEmptyMessage(MSG_POST_CONFIGURATION_CHANGED);
}
};
/** When configuration changes, this is called after the UI thread is idle. */
private static final int MSG_POST_CONFIGURATION_CHANGED = 2;
/** Used to delay the zoom controller dismissal. */
private static final int MSG_DISMISS_ZOOM_CONTROLS = 3;
/**
* If setVisible(true) is called and the owner view's window token is null,
* we delay the setVisible(true) call until it is not null.
*/
private static final int MSG_POST_SET_VISIBLE = 4;
private final Handler mHandler = new Handler() {
@Override
public void handleMessage(Message msg) {
switch (msg.what) {
case MSG_POST_CONFIGURATION_CHANGED:
onPostConfigurationChanged();
break;
case MSG_DISMISS_ZOOM_CONTROLS:
setVisible(false);
break;
case MSG_POST_SET_VISIBLE:
if (mOwnerView.getWindowToken() == null) {
// Doh, it is still null, just ignore the set visible call
Log.e(TAG,
"Cannot make the zoom controller visible if the owner view is " +
"not attached to a window.");
} else {
setVisible(true);
}
break;
}
}
};
/**
* Constructor for the {@link ZoomButtonsController}.
*
* @param ownerView The view that is being zoomed by the zoom controls. The
* zoom controls will be displayed aligned with this view.
*/
public ZoomButtonsController(View ownerView) {
mContext = ownerView.getContext();
mWindowManager = (WindowManager) mContext.getSystemService(Context.WINDOW_SERVICE);
mOwnerView = ownerView;
mTouchPaddingScaledSq = (int)
(ZOOM_CONTROLS_TOUCH_PADDING * mContext.getResources().getDisplayMetrics().density);
mTouchPaddingScaledSq *= mTouchPaddingScaledSq;
mContainer = createContainer();
}
/**
* Whether to enable the zoom in control.
*
* @param enabled Whether to enable the zoom in control.
*/
public void setZoomInEnabled(boolean enabled) {
mControls.setIsZoomInEnabled(enabled);
}
/**
* Whether to enable the zoom out control.
*
* @param enabled Whether to enable the zoom out control.
*/
public void setZoomOutEnabled(boolean enabled) {
mControls.setIsZoomOutEnabled(enabled);
}
/**
* Sets the delay between zoom callbacks as the user holds a zoom button.
*
* @param speed The delay in milliseconds between zoom callbacks.
*/
public void setZoomSpeed(long speed) {
mControls.setZoomSpeed(speed);
}
private FrameLayout createContainer() {
LayoutParams lp = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
// Controls are positioned BOTTOM | CENTER with respect to the owner view.
lp.gravity = Gravity.TOP | Gravity.START;
lp.flags = LayoutParams.FLAG_NOT_TOUCHABLE |
LayoutParams.FLAG_NOT_FOCUSABLE |
LayoutParams.FLAG_LAYOUT_NO_LIMITS |
LayoutParams.FLAG_ALT_FOCUSABLE_IM;
lp.height = LayoutParams.WRAP_CONTENT;
lp.width = LayoutParams.MATCH_PARENT;
lp.type = LayoutParams.TYPE_APPLICATION_PANEL;
lp.format = PixelFormat.TRANSLUCENT;
lp.windowAnimations = com.android.internal.R.style.Animation_ZoomButtons;
mContainerLayoutParams = lp;
FrameLayout container = new Container(mContext);
container.setLayoutParams(lp);
container.setMeasureAllChildren(true);
LayoutInflater inflater = (LayoutInflater) mContext
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
inflater.inflate(com.android.internal.R.layout.zoom_container, container);
mControls = (ZoomControls) container.findViewById(com.android.internal.R.id.zoomControls);
mControls.setOnZoomInClickListener(new OnClickListener() {
public void onClick(View v) {
dismissControlsDelayed(ZOOM_CONTROLS_TIMEOUT);
if (mCallback != null) mCallback.onZoom(true);
}
});
mControls.setOnZoomOutClickListener(new OnClickListener() {
public void onClick(View v) {
dismissControlsDelayed(ZOOM_CONTROLS_TIMEOUT);
if (mCallback != null) mCallback.onZoom(false);
}
});
return container;
}
/**
* Sets the {@link OnZoomListener} listener that receives callbacks to zoom.
*
* @param listener The listener that will be told to zoom.
*/
public void setOnZoomListener(OnZoomListener listener) {
mCallback = listener;
}
/**
* Sets whether the zoom controls should be focusable. If the controls are
* focusable, then trackball and arrow key interactions are possible.
* Otherwise, only touch interactions are possible.
*
* @param focusable Whether the zoom controls should be focusable.
*/
public void setFocusable(boolean focusable) {
int oldFlags = mContainerLayoutParams.flags;
if (focusable) {
mContainerLayoutParams.flags &= ~LayoutParams.FLAG_NOT_FOCUSABLE;
} else {
mContainerLayoutParams.flags |= LayoutParams.FLAG_NOT_FOCUSABLE;
}
if ((mContainerLayoutParams.flags != oldFlags) && mIsVisible) {
mWindowManager.updateViewLayout(mContainer, mContainerLayoutParams);
}
}
/**
* Whether the zoom controls will be automatically dismissed after showing.
*
* @return Whether the zoom controls will be auto dismissed after showing.
*/
public boolean isAutoDismissed() {
return mAutoDismissControls;
}
/**
* Sets whether the zoom controls will be automatically dismissed after
* showing.
*/
public void setAutoDismissed(boolean autoDismiss) {
if (mAutoDismissControls == autoDismiss) return;
mAutoDismissControls = autoDismiss;
}
/**
* Whether the zoom controls are visible to the user.
*
* @return Whether the zoom controls are visible to the user.
*/
public boolean isVisible() {
return mIsVisible;
}
/**
* Sets whether the zoom controls should be visible to the user.
*
* @param visible Whether the zoom controls should be visible to the user.
*/
public void setVisible(boolean visible) {
if (visible) {
if (mOwnerView.getWindowToken() == null) {
/*
* We need a window token to show ourselves, maybe the owner's
* window hasn't been created yet but it will have been by the
* time the looper is idle, so post the setVisible(true) call.
*/
if (!mHandler.hasMessages(MSG_POST_SET_VISIBLE)) {
mHandler.sendEmptyMessage(MSG_POST_SET_VISIBLE);
}
return;
}
dismissControlsDelayed(ZOOM_CONTROLS_TIMEOUT);
}
if (mIsVisible == visible) {
return;
}
mIsVisible = visible;
if (visible) {
if (mContainerLayoutParams.token == null) {
mContainerLayoutParams.token = mOwnerView.getWindowToken();
}
mWindowManager.addView(mContainer, mContainerLayoutParams);
if (mPostedVisibleInitializer == null) {
mPostedVisibleInitializer = new Runnable() {
public void run() {
refreshPositioningVariables();
if (mCallback != null) {
mCallback.onVisibilityChanged(true);
}
}
};
}
mHandler.post(mPostedVisibleInitializer);
// Handle configuration changes when visible
mContext.registerReceiver(mConfigurationChangedReceiver, mConfigurationChangedFilter);
// Steal touches events from the owner
mOwnerView.setOnTouchListener(this);
mReleaseTouchListenerOnUp = false;
} else {
// Don't want to steal any more touches
if (mTouchTargetView != null) {
// We are still stealing the touch events for this touch
// sequence, so release the touch listener later
mReleaseTouchListenerOnUp = true;
} else {
mOwnerView.setOnTouchListener(null);
}
// No longer care about configuration changes
mContext.unregisterReceiver(mConfigurationChangedReceiver);
mWindowManager.removeView(mContainer);
mHandler.removeCallbacks(mPostedVisibleInitializer);
if (mCallback != null) {
mCallback.onVisibilityChanged(false);
}
}
}
/**
* Gets the container that is the parent of the zoom controls.
*
* The client can add other views to this container to link them with the
* zoom controls.
*
* @return The container of the zoom controls. It will be a layout that
* respects the gravity of a child's layout parameters.
*/
public ViewGroup getContainer() {
return mContainer;
}
/**
* Gets the view for the zoom controls.
*
* @return The zoom controls view.
*/
public View getZoomControls() {
return mControls;
}
private void dismissControlsDelayed(int delay) {
if (mAutoDismissControls) {
mHandler.removeMessages(MSG_DISMISS_ZOOM_CONTROLS);
mHandler.sendEmptyMessageDelayed(MSG_DISMISS_ZOOM_CONTROLS, delay);
}
}
private void refreshPositioningVariables() {
// if the mOwnerView is detached from window then skip.
if (mOwnerView.getWindowToken() == null) return;
// Position the zoom controls on the bottom of the owner view.
int ownerHeight = mOwnerView.getHeight();
int ownerWidth = mOwnerView.getWidth();
// The gap between the top of the owner and the top of the container
int containerOwnerYOffset = ownerHeight - mContainer.getHeight();
// Calculate the owner view's bounds
mOwnerView.getLocationOnScreen(mOwnerViewRawLocation);
mContainerRawLocation[0] = mOwnerViewRawLocation[0];
mContainerRawLocation[1] = mOwnerViewRawLocation[1] + containerOwnerYOffset;
int[] ownerViewWindowLoc = mTempIntArray;
mOwnerView.getLocationInWindow(ownerViewWindowLoc);
// lp.x and lp.y should be relative to the owner's window top-left
mContainerLayoutParams.x = ownerViewWindowLoc[0];
mContainerLayoutParams.width = ownerWidth;
mContainerLayoutParams.y = ownerViewWindowLoc[1] + containerOwnerYOffset;
if (mIsVisible) {
mWindowManager.updateViewLayout(mContainer, mContainerLayoutParams);
}
}
/* This will only be called when the container has focus. */
private boolean onContainerKey(KeyEvent event) {
int keyCode = event.getKeyCode();
if (isInterestingKey(keyCode)) {
if (keyCode == KeyEvent.KEYCODE_BACK) {
if (event.getAction() == KeyEvent.ACTION_DOWN
&& event.getRepeatCount() == 0) {
if (mOwnerView != null) {
KeyEvent.DispatcherState ds = mOwnerView.getKeyDispatcherState();
if (ds != null) {
ds.startTracking(event, this);
}
}
return true;
} else if (event.getAction() == KeyEvent.ACTION_UP
&& event.isTracking() && !event.isCanceled()) {
setVisible(false);
return true;
}
} else {
dismissControlsDelayed(ZOOM_CONTROLS_TIMEOUT);
}
// Let the container handle the key
return false;
} else {
ViewRootImpl viewRoot = mOwnerView.getViewRootImpl();
if (viewRoot != null) {
viewRoot.dispatchInputEvent(event);
}
// We gave the key to the owner, don't let the container handle this key
return true;
}
}
private boolean isInterestingKey(int keyCode) {
switch (keyCode) {
case KeyEvent.KEYCODE_DPAD_CENTER:
case KeyEvent.KEYCODE_DPAD_UP:
case KeyEvent.KEYCODE_DPAD_DOWN:
case KeyEvent.KEYCODE_DPAD_LEFT:
case KeyEvent.KEYCODE_DPAD_RIGHT:
case KeyEvent.KEYCODE_ENTER:
case KeyEvent.KEYCODE_BACK:
return true;
default:
return false;
}
}
/**
* @hide The ZoomButtonsController implements the OnTouchListener, but this
* does not need to be shown in its public API.
*/
public boolean onTouch(View v, MotionEvent event) {
int action = event.getAction();
if (event.getPointerCount() > 1) {
// ZoomButtonsController doesn't handle mutitouch. Give up control.
return false;
}
if (mReleaseTouchListenerOnUp) {
// The controls were dismissed but we need to throw away all events until the up
if (action == MotionEvent.ACTION_UP || action == MotionEvent.ACTION_CANCEL) {
mOwnerView.setOnTouchListener(null);
setTouchTargetView(null);
mReleaseTouchListenerOnUp = false;
}
// Eat this event
return true;
}
dismissControlsDelayed(ZOOM_CONTROLS_TIMEOUT);
View targetView = mTouchTargetView;
switch (action) {
case MotionEvent.ACTION_DOWN:
targetView = findViewForTouch((int) event.getRawX(), (int) event.getRawY());
setTouchTargetView(targetView);
break;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_CANCEL:
setTouchTargetView(null);
break;
}
if (targetView != null) {
// The upperleft corner of the target view in raw coordinates
int targetViewRawX = mContainerRawLocation[0] + mTouchTargetWindowLocation[0];
int targetViewRawY = mContainerRawLocation[1] + mTouchTargetWindowLocation[1];
MotionEvent containerEvent = MotionEvent.obtain(event);
// Convert the motion event into the target view's coordinates (from
// owner view's coordinates)
containerEvent.offsetLocation(mOwnerViewRawLocation[0] - targetViewRawX,
mOwnerViewRawLocation[1] - targetViewRawY);
/* Disallow negative coordinates (which can occur due to
* ZOOM_CONTROLS_TOUCH_PADDING) */
// These are floats because we need to potentially offset away this exact amount
float containerX = containerEvent.getX();
float containerY = containerEvent.getY();
if (containerX < 0 && containerX > -ZOOM_CONTROLS_TOUCH_PADDING) {
containerEvent.offsetLocation(-containerX, 0);
}
if (containerY < 0 && containerY > -ZOOM_CONTROLS_TOUCH_PADDING) {
containerEvent.offsetLocation(0, -containerY);
}
boolean retValue = targetView.dispatchTouchEvent(containerEvent);
containerEvent.recycle();
return retValue;
} else {
return false;
}
}
private void setTouchTargetView(View view) {
mTouchTargetView = view;
if (view != null) {
view.getLocationInWindow(mTouchTargetWindowLocation);
}
}
/**
* Returns the View that should receive a touch at the given coordinates.
*
* @param rawX The raw X.
* @param rawY The raw Y.
* @return The view that should receive the touches, or null if there is not one.
*/
private View findViewForTouch(int rawX, int rawY) {
// Reverse order so the child drawn on top gets first dibs.
int containerCoordsX = rawX - mContainerRawLocation[0];
int containerCoordsY = rawY - mContainerRawLocation[1];
Rect frame = mTempRect;
View closestChild = null;
int closestChildDistanceSq = Integer.MAX_VALUE;
for (int i = mContainer.getChildCount() - 1; i >= 0; i--) {
View child = mContainer.getChildAt(i);
if (child.getVisibility() != View.VISIBLE) {
continue;
}
child.getHitRect(frame);
if (frame.contains(containerCoordsX, containerCoordsY)) {
return child;
}
int distanceX;
if (containerCoordsX >= frame.left && containerCoordsX <= frame.right) {
distanceX = 0;
} else {
distanceX = Math.min(Math.abs(frame.left - containerCoordsX),
Math.abs(containerCoordsX - frame.right));
}
int distanceY;
if (containerCoordsY >= frame.top && containerCoordsY <= frame.bottom) {
distanceY = 0;
} else {
distanceY = Math.min(Math.abs(frame.top - containerCoordsY),
Math.abs(containerCoordsY - frame.bottom));
}
int distanceSq = distanceX * distanceX + distanceY * distanceY;
if ((distanceSq < mTouchPaddingScaledSq) &&
(distanceSq < closestChildDistanceSq)) {
closestChild = child;
closestChildDistanceSq = distanceSq;
}
}
return closestChild;
}
private void onPostConfigurationChanged() {
dismissControlsDelayed(ZOOM_CONTROLS_TIMEOUT);
refreshPositioningVariables();
}
/**
* Interface that will be called when the user performs an interaction that
* triggers some action, for example zooming.
*/
public interface OnZoomListener {
/**
* Called when the zoom controls' visibility changes.
*
* @param visible Whether the zoom controls are visible.
*/
void onVisibilityChanged(boolean visible);
/**
* Called when the owner view needs to be zoomed.
*
* @param zoomIn The direction of the zoom: true to zoom in, false to zoom out.
*/
void onZoom(boolean zoomIn);
}
private class Container extends FrameLayout {
public Container(Context context) {
super(context);
}
/*
* Need to override this to intercept the key events. Otherwise, we
* would attach a key listener to the container but its superclass
* ViewGroup gives it to the focused View instead of calling the key
* listener, and so we wouldn't get the events.
*/
@Override
public boolean dispatchKeyEvent(KeyEvent event) {
return onContainerKey(event) ? true : super.dispatchKeyEvent(event);
}
}
}