/*
* Copyright (C) 2010 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 com.android.internal.R;
import com.android.internal.view.menu.MenuBuilder;
import com.android.internal.view.menu.MenuPopupHelper;
import com.android.internal.view.menu.ShowableListMenu;
import android.annotation.MenuRes;
import android.content.Context;
import android.view.Gravity;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnTouchListener;
/**
* A PopupMenu displays a {@link Menu} in a modal popup window anchored to a
* {@link View}. The popup will appear below the anchor view if there is room,
* or above it if there is not. If the IME is visible the popup will not
* overlap it until it is touched. Touching outside of the popup will dismiss
* it.
*/
public class PopupMenu {
private final Context mContext;
private final MenuBuilder mMenu;
private final View mAnchor;
private final MenuPopupHelper mPopup;
private OnMenuItemClickListener mMenuItemClickListener;
private OnDismissListener mOnDismissListener;
private OnTouchListener mDragListener;
/**
* Constructor to create a new popup menu with an anchor view.
*
* @param context Context the popup menu is running in, through which it
* can access the current theme, resources, etc.
* @param anchor Anchor view for this popup. The popup will appear below
* the anchor if there is room, or above it if there is not.
*/
public PopupMenu(Context context, View anchor) {
this(context, anchor, Gravity.NO_GRAVITY);
}
/**
* Constructor to create a new popup menu with an anchor view and alignment
* gravity.
*
* @param context Context the popup menu is running in, through which it
* can access the current theme, resources, etc.
* @param anchor Anchor view for this popup. The popup will appear below
* the anchor if there is room, or above it if there is not.
* @param gravity The {@link Gravity} value for aligning the popup with its
* anchor.
*/
public PopupMenu(Context context, View anchor, int gravity) {
this(context, anchor, gravity, R.attr.popupMenuStyle, 0);
}
/**
* Constructor a create a new popup menu with a specific style.
*
* @param context Context the popup menu is running in, through which it
* can access the current theme, resources, etc.
* @param anchor Anchor view for this popup. The popup will appear below
* the anchor if there is room, or above it if there is not.
* @param gravity The {@link Gravity} value for aligning the popup with its
* anchor.
* @param popupStyleAttr An attribute in the current theme that contains a
* reference to a style resource that supplies default values for
* the popup window. Can be 0 to not look for defaults.
* @param popupStyleRes A resource identifier of a style resource that
* supplies default values for the popup window, used only if
* popupStyleAttr is 0 or can not be found in the theme. Can be 0
* to not look for defaults.
*/
public PopupMenu(Context context, View anchor, int gravity, int popupStyleAttr,
int popupStyleRes) {
mContext = context;
mAnchor = anchor;
mMenu = new MenuBuilder(context);
mMenu.setCallback(new MenuBuilder.Callback() {
@Override
public boolean onMenuItemSelected(MenuBuilder menu, MenuItem item) {
if (mMenuItemClickListener != null) {
return mMenuItemClickListener.onMenuItemClick(item);
}
return false;
}
@Override
public void onMenuModeChange(MenuBuilder menu) {
}
});
mPopup = new MenuPopupHelper(context, mMenu, anchor, false, popupStyleAttr, popupStyleRes);
mPopup.setGravity(gravity);
mPopup.setOnDismissListener(new PopupWindow.OnDismissListener() {
@Override
public void onDismiss() {
if (mOnDismissListener != null) {
mOnDismissListener.onDismiss(PopupMenu.this);
}
}
});
}
/**
* Sets the gravity used to align the popup window to its anchor view.
* <p>
* If the popup is showing, calling this method will take effect only
* the next time the popup is shown.
*
* @param gravity the gravity used to align the popup window
* @see #getGravity()
*/
public void setGravity(int gravity) {
mPopup.setGravity(gravity);
}
/**
* @return the gravity used to align the popup window to its anchor view
* @see #setGravity(int)
*/
public int getGravity() {
return mPopup.getGravity();
}
/**
* Returns an {@link OnTouchListener} that can be added to the anchor view
* to implement drag-to-open behavior.
* <p>
* When the listener is set on a view, touching that view and dragging
* outside of its bounds will open the popup window. Lifting will select
* the currently touched list item.
* <p>
* Example usage:
* <pre>
* PopupMenu myPopup = new PopupMenu(context, myAnchor);
* myAnchor.setOnTouchListener(myPopup.getDragToOpenListener());
* </pre>
*
* @return a touch listener that controls drag-to-open behavior
*/
public OnTouchListener getDragToOpenListener() {
if (mDragListener == null) {
mDragListener = new ForwardingListener(mAnchor) {
@Override
protected boolean onForwardingStarted() {
show();
return true;
}
@Override
protected boolean onForwardingStopped() {
dismiss();
return true;
}
@Override
public ShowableListMenu getPopup() {
// This will be null until show() is called.
return mPopup.getPopup();
}
};
}
return mDragListener;
}
/**
* Returns the {@link Menu} associated with this popup. Populate the
* returned Menu with items before calling {@link #show()}.
*
* @return the {@link Menu} associated with this popup
* @see #show()
* @see #getMenuInflater()
*/
public Menu getMenu() {
return mMenu;
}
/**
* @return a {@link MenuInflater} that can be used to inflate menu items
* from XML into the menu returned by {@link #getMenu()}
* @see #getMenu()
*/
public MenuInflater getMenuInflater() {
return new MenuInflater(mContext);
}
/**
* Inflate a menu resource into this PopupMenu. This is equivalent to
* calling {@code popupMenu.getMenuInflater().inflate(menuRes, popupMenu.getMenu())}.
*
* @param menuRes Menu resource to inflate
*/
public void inflate(@MenuRes int menuRes) {
getMenuInflater().inflate(menuRes, mMenu);
}
/**
* Show the menu popup anchored to the view specified during construction.
*
* @see #dismiss()
*/
public void show() {
mPopup.show();
}
/**
* Dismiss the menu popup.
*
* @see #show()
*/
public void dismiss() {
mPopup.dismiss();
}
/**
* Sets a listener that will be notified when the user selects an item from
* the menu.
*
* @param listener the listener to notify
*/
public void setOnMenuItemClickListener(OnMenuItemClickListener listener) {
mMenuItemClickListener = listener;
}
/**
* Sets a listener that will be notified when this menu is dismissed.
*
* @param listener the listener to notify
*/
public void setOnDismissListener(OnDismissListener listener) {
mOnDismissListener = listener;
}
/**
* Interface responsible for receiving menu item click events if the items
* themselves do not have individual item click listeners.
*/
public interface OnMenuItemClickListener {
/**
* This method will be invoked when a menu item is clicked if the item
* itself did not already handle the event.
*
* @param item the menu item that was clicked
* @return {@code true} if the event was handled, {@code false}
* otherwise
*/
boolean onMenuItemClick(MenuItem item);
}
/**
* Callback interface used to notify the application that the menu has closed.
*/
public interface OnDismissListener {
/**
* Called when the associated menu has been dismissed.
*
* @param menu the popup menu that was dismissed
*/
void onDismiss(PopupMenu menu);
}
}