1 /*
2  * Copyright (C) 2007 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package android.widget;
18 
19 import android.annotation.IntDef;
20 import android.annotation.StringRes;
21 import android.app.INotificationManager;
22 import android.app.ITransientNotification;
23 import android.content.Context;
24 import android.content.res.Configuration;
25 import android.content.res.Resources;
26 import android.graphics.PixelFormat;
27 import android.os.Handler;
28 import android.os.RemoteException;
29 import android.os.ServiceManager;
30 import android.util.Log;
31 import android.view.Gravity;
32 import android.view.LayoutInflater;
33 import android.view.View;
34 import android.view.WindowManager;
35 import android.view.accessibility.AccessibilityEvent;
36 import android.view.accessibility.AccessibilityManager;
37 
38 import java.lang.annotation.Retention;
39 import java.lang.annotation.RetentionPolicy;
40 
41 /**
42  * A toast is a view containing a quick little message for the user.  The toast class
43  * helps you create and show those.
44  * {@more}
45  *
46  * <p>
47  * When the view is shown to the user, appears as a floating view over the
48  * application.  It will never receive focus.  The user will probably be in the
49  * middle of typing something else.  The idea is to be as unobtrusive as
50  * possible, while still showing the user the information you want them to see.
51  * Two examples are the volume control, and the brief message saying that your
52  * settings have been saved.
53  * <p>
54  * The easiest way to use this class is to call one of the static methods that constructs
55  * everything you need and returns a new Toast object.
56  *
57  * <div class="special reference">
58  * <h3>Developer Guides</h3>
59  * <p>For information about creating Toast notifications, read the
60  * <a href="{@docRoot}guide/topics/ui/notifiers/toasts.html">Toast Notifications</a> developer
61  * guide.</p>
62  * </div>
63  */
64 public class Toast {
65     static final String TAG = "Toast";
66     static final boolean localLOGV = false;
67 
68     /** @hide */
69     @IntDef({LENGTH_SHORT, LENGTH_LONG})
70     @Retention(RetentionPolicy.SOURCE)
71     public @interface Duration {}
72 
73     /**
74      * Show the view or text notification for a short period of time.  This time
75      * could be user-definable.  This is the default.
76      * @see #setDuration
77      */
78     public static final int LENGTH_SHORT = 0;
79 
80     /**
81      * Show the view or text notification for a long period of time.  This time
82      * could be user-definable.
83      * @see #setDuration
84      */
85     public static final int LENGTH_LONG = 1;
86 
87     final Context mContext;
88     final TN mTN;
89     int mDuration;
90     View mNextView;
91 
92     /**
93      * Construct an empty Toast object.  You must call {@link #setView} before you
94      * can call {@link #show}.
95      *
96      * @param context  The context to use.  Usually your {@link android.app.Application}
97      *                 or {@link android.app.Activity} object.
98      */
Toast(Context context)99     public Toast(Context context) {
100         mContext = context;
101         mTN = new TN();
102         mTN.mY = context.getResources().getDimensionPixelSize(
103                 com.android.internal.R.dimen.toast_y_offset);
104         mTN.mGravity = context.getResources().getInteger(
105                 com.android.internal.R.integer.config_toastDefaultGravity);
106     }
107 
108     /**
109      * Show the view for the specified duration.
110      */
show()111     public void show() {
112         if (mNextView == null) {
113             throw new RuntimeException("setView must have been called");
114         }
115 
116         INotificationManager service = getService();
117         String pkg = mContext.getOpPackageName();
118         TN tn = mTN;
119         tn.mNextView = mNextView;
120 
121         try {
122             service.enqueueToast(pkg, tn, mDuration);
123         } catch (RemoteException e) {
124             // Empty
125         }
126     }
127 
128     /**
129      * Close the view if it's showing, or don't show it if it isn't showing yet.
130      * You do not normally have to call this.  Normally view will disappear on its own
131      * after the appropriate duration.
132      */
cancel()133     public void cancel() {
134         mTN.hide();
135 
136         try {
137             getService().cancelToast(mContext.getPackageName(), mTN);
138         } catch (RemoteException e) {
139             // Empty
140         }
141     }
142 
143     /**
144      * Set the view to show.
145      * @see #getView
146      */
setView(View view)147     public void setView(View view) {
148         mNextView = view;
149     }
150 
151     /**
152      * Return the view.
153      * @see #setView
154      */
getView()155     public View getView() {
156         return mNextView;
157     }
158 
159     /**
160      * Set how long to show the view for.
161      * @see #LENGTH_SHORT
162      * @see #LENGTH_LONG
163      */
setDuration(@uration int duration)164     public void setDuration(@Duration int duration) {
165         mDuration = duration;
166     }
167 
168     /**
169      * Return the duration.
170      * @see #setDuration
171      */
172     @Duration
getDuration()173     public int getDuration() {
174         return mDuration;
175     }
176 
177     /**
178      * Set the margins of the view.
179      *
180      * @param horizontalMargin The horizontal margin, in percentage of the
181      *        container width, between the container's edges and the
182      *        notification
183      * @param verticalMargin The vertical margin, in percentage of the
184      *        container height, between the container's edges and the
185      *        notification
186      */
setMargin(float horizontalMargin, float verticalMargin)187     public void setMargin(float horizontalMargin, float verticalMargin) {
188         mTN.mHorizontalMargin = horizontalMargin;
189         mTN.mVerticalMargin = verticalMargin;
190     }
191 
192     /**
193      * Return the horizontal margin.
194      */
getHorizontalMargin()195     public float getHorizontalMargin() {
196         return mTN.mHorizontalMargin;
197     }
198 
199     /**
200      * Return the vertical margin.
201      */
getVerticalMargin()202     public float getVerticalMargin() {
203         return mTN.mVerticalMargin;
204     }
205 
206     /**
207      * Set the location at which the notification should appear on the screen.
208      * @see android.view.Gravity
209      * @see #getGravity
210      */
setGravity(int gravity, int xOffset, int yOffset)211     public void setGravity(int gravity, int xOffset, int yOffset) {
212         mTN.mGravity = gravity;
213         mTN.mX = xOffset;
214         mTN.mY = yOffset;
215     }
216 
217      /**
218      * Get the location at which the notification should appear on the screen.
219      * @see android.view.Gravity
220      * @see #getGravity
221      */
getGravity()222     public int getGravity() {
223         return mTN.mGravity;
224     }
225 
226     /**
227      * Return the X offset in pixels to apply to the gravity's location.
228      */
getXOffset()229     public int getXOffset() {
230         return mTN.mX;
231     }
232 
233     /**
234      * Return the Y offset in pixels to apply to the gravity's location.
235      */
getYOffset()236     public int getYOffset() {
237         return mTN.mY;
238     }
239 
240     /**
241      * Gets the LayoutParams for the Toast window.
242      * @hide
243      */
getWindowParams()244     public WindowManager.LayoutParams getWindowParams() {
245         return mTN.mParams;
246     }
247 
248     /**
249      * Make a standard toast that just contains a text view.
250      *
251      * @param context  The context to use.  Usually your {@link android.app.Application}
252      *                 or {@link android.app.Activity} object.
253      * @param text     The text to show.  Can be formatted text.
254      * @param duration How long to display the message.  Either {@link #LENGTH_SHORT} or
255      *                 {@link #LENGTH_LONG}
256      *
257      */
makeText(Context context, CharSequence text, @Duration int duration)258     public static Toast makeText(Context context, CharSequence text, @Duration int duration) {
259         Toast result = new Toast(context);
260 
261         LayoutInflater inflate = (LayoutInflater)
262                 context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
263         View v = inflate.inflate(com.android.internal.R.layout.transient_notification, null);
264         TextView tv = (TextView)v.findViewById(com.android.internal.R.id.message);
265         tv.setText(text);
266 
267         result.mNextView = v;
268         result.mDuration = duration;
269 
270         return result;
271     }
272 
273     /**
274      * Make a standard toast that just contains a text view with the text from a resource.
275      *
276      * @param context  The context to use.  Usually your {@link android.app.Application}
277      *                 or {@link android.app.Activity} object.
278      * @param resId    The resource id of the string resource to use.  Can be formatted text.
279      * @param duration How long to display the message.  Either {@link #LENGTH_SHORT} or
280      *                 {@link #LENGTH_LONG}
281      *
282      * @throws Resources.NotFoundException if the resource can't be found.
283      */
makeText(Context context, @StringRes int resId, @Duration int duration)284     public static Toast makeText(Context context, @StringRes int resId, @Duration int duration)
285                                 throws Resources.NotFoundException {
286         return makeText(context, context.getResources().getText(resId), duration);
287     }
288 
289     /**
290      * Update the text in a Toast that was previously created using one of the makeText() methods.
291      * @param resId The new text for the Toast.
292      */
setText(@tringRes int resId)293     public void setText(@StringRes int resId) {
294         setText(mContext.getText(resId));
295     }
296 
297     /**
298      * Update the text in a Toast that was previously created using one of the makeText() methods.
299      * @param s The new text for the Toast.
300      */
setText(CharSequence s)301     public void setText(CharSequence s) {
302         if (mNextView == null) {
303             throw new RuntimeException("This Toast was not created with Toast.makeText()");
304         }
305         TextView tv = (TextView) mNextView.findViewById(com.android.internal.R.id.message);
306         if (tv == null) {
307             throw new RuntimeException("This Toast was not created with Toast.makeText()");
308         }
309         tv.setText(s);
310     }
311 
312     // =======================================================================================
313     // All the gunk below is the interaction with the Notification Service, which handles
314     // the proper ordering of these system-wide.
315     // =======================================================================================
316 
317     private static INotificationManager sService;
318 
getService()319     static private INotificationManager getService() {
320         if (sService != null) {
321             return sService;
322         }
323         sService = INotificationManager.Stub.asInterface(ServiceManager.getService("notification"));
324         return sService;
325     }
326 
327     private static class TN extends ITransientNotification.Stub {
328         final Runnable mShow = new Runnable() {
329             @Override
330             public void run() {
331                 handleShow();
332             }
333         };
334 
335         final Runnable mHide = new Runnable() {
336             @Override
337             public void run() {
338                 handleHide();
339                 // Don't do this in handleHide() because it is also invoked by handleShow()
340                 mNextView = null;
341             }
342         };
343 
344         private final WindowManager.LayoutParams mParams = new WindowManager.LayoutParams();
345         final Handler mHandler = new Handler();
346 
347         int mGravity;
348         int mX, mY;
349         float mHorizontalMargin;
350         float mVerticalMargin;
351 
352 
353         View mView;
354         View mNextView;
355 
356         WindowManager mWM;
357 
TN()358         TN() {
359             // XXX This should be changed to use a Dialog, with a Theme.Toast
360             // defined that sets up the layout params appropriately.
361             final WindowManager.LayoutParams params = mParams;
362             params.height = WindowManager.LayoutParams.WRAP_CONTENT;
363             params.width = WindowManager.LayoutParams.WRAP_CONTENT;
364             params.format = PixelFormat.TRANSLUCENT;
365             params.windowAnimations = com.android.internal.R.style.Animation_Toast;
366             params.type = WindowManager.LayoutParams.TYPE_TOAST;
367             params.setTitle("Toast");
368             params.flags = WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON
369                     | WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE
370                     | WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE;
371         }
372 
373         /**
374          * schedule handleShow into the right thread
375          */
376         @Override
show()377         public void show() {
378             if (localLOGV) Log.v(TAG, "SHOW: " + this);
379             mHandler.post(mShow);
380         }
381 
382         /**
383          * schedule handleHide into the right thread
384          */
385         @Override
hide()386         public void hide() {
387             if (localLOGV) Log.v(TAG, "HIDE: " + this);
388             mHandler.post(mHide);
389         }
390 
handleShow()391         public void handleShow() {
392             if (localLOGV) Log.v(TAG, "HANDLE SHOW: " + this + " mView=" + mView
393                     + " mNextView=" + mNextView);
394             if (mView != mNextView) {
395                 // remove the old view if necessary
396                 handleHide();
397                 mView = mNextView;
398                 Context context = mView.getContext().getApplicationContext();
399                 String packageName = mView.getContext().getOpPackageName();
400                 if (context == null) {
401                     context = mView.getContext();
402                 }
403                 mWM = (WindowManager)context.getSystemService(Context.WINDOW_SERVICE);
404                 // We can resolve the Gravity here by using the Locale for getting
405                 // the layout direction
406                 final Configuration config = mView.getContext().getResources().getConfiguration();
407                 final int gravity = Gravity.getAbsoluteGravity(mGravity, config.getLayoutDirection());
408                 mParams.gravity = gravity;
409                 if ((gravity & Gravity.HORIZONTAL_GRAVITY_MASK) == Gravity.FILL_HORIZONTAL) {
410                     mParams.horizontalWeight = 1.0f;
411                 }
412                 if ((gravity & Gravity.VERTICAL_GRAVITY_MASK) == Gravity.FILL_VERTICAL) {
413                     mParams.verticalWeight = 1.0f;
414                 }
415                 mParams.x = mX;
416                 mParams.y = mY;
417                 mParams.verticalMargin = mVerticalMargin;
418                 mParams.horizontalMargin = mHorizontalMargin;
419                 mParams.packageName = packageName;
420                 if (mView.getParent() != null) {
421                     if (localLOGV) Log.v(TAG, "REMOVE! " + mView + " in " + this);
422                     mWM.removeView(mView);
423                 }
424                 if (localLOGV) Log.v(TAG, "ADD! " + mView + " in " + this);
425                 mWM.addView(mView, mParams);
426                 trySendAccessibilityEvent();
427             }
428         }
429 
trySendAccessibilityEvent()430         private void trySendAccessibilityEvent() {
431             AccessibilityManager accessibilityManager =
432                     AccessibilityManager.getInstance(mView.getContext());
433             if (!accessibilityManager.isEnabled()) {
434                 return;
435             }
436             // treat toasts as notifications since they are used to
437             // announce a transient piece of information to the user
438             AccessibilityEvent event = AccessibilityEvent.obtain(
439                     AccessibilityEvent.TYPE_NOTIFICATION_STATE_CHANGED);
440             event.setClassName(getClass().getName());
441             event.setPackageName(mView.getContext().getPackageName());
442             mView.dispatchPopulateAccessibilityEvent(event);
443             accessibilityManager.sendAccessibilityEvent(event);
444         }
445 
handleHide()446         public void handleHide() {
447             if (localLOGV) Log.v(TAG, "HANDLE HIDE: " + this + " mView=" + mView);
448             if (mView != null) {
449                 // note: checking parent() just to make sure the view has
450                 // been added...  i have seen cases where we get here when
451                 // the view isn't yet added, so let's try not to crash.
452                 if (mView.getParent() != null) {
453                     if (localLOGV) Log.v(TAG, "REMOVE! " + mView + " in " + this);
454                     mWM.removeView(mView);
455                 }
456 
457                 mView = null;
458             }
459         }
460     }
461 }
462