In Andriod, when you select text, a menu appears with actions that you can perform: Cut, Copy, Submit. Android Marshmallow (SDK 23) has the opportunity to expand this menu and give the user easy access to additional features when working with the text: "Translate", "Comment", "Quote".

In preparation for speaking at the GDG conference in Nizhny Novgorod, I discovered that this new feature is extremely poorly documented, the only available article is not entirely true, and there are vanishingly few examples on the Internet of using this feature. I had to figure it out myself. The results of the study and I want to share. This can save you a lot of time.

Since various menus in Android appeared evolutionarily, it’s easiest to start the story “from the stove”. Developers with experience can boldly flip right through to the “New” section without any risk of missing anything. If that - then come back. Younger developers can find useful examples in practice under spoilers.

Old

The first. Vulgaris menu

The second. Context menu

Third. Menu in AppBar and Toolbar

Fourth. Contextual action mode

New

In Android Marshmallow (aka 6.0, aka SDK 23), two innovations appeared in the menu. Both of these innovations are not yet supported by the Support Library and only work on devices with SDK 23. Therefore, before calling the methods that appeared, you need to check the SDK number of the device on which the application is running.

For the convenience of the story, we will get rid of these checks by specifying minSdkVersion 23.

The fifth. Another context menu

The method for creating the “Context Action Mode” (described above) has been extended. The second parameter startActionMode () can pass a constant that specifies the type of display.

The value of ActionMode.TYPE_PRIMARY corresponds to the old behavior. That is, startActionMode (actionModeCallback) and startActionMode (actionModeCallback, ActionMode.TYPE_PRIMARY) are the same.

If you specify the type ActionMode.TYPE_FLOATING , the menu takes the following form:



No icons. Location - horizontal.

If there are so many points that they do not fit in width, then the familiar “three points” will appear:

Everything else is exactly the same as in “Contextual action mode” (see above).

The sixth. Expansion of the menu when selecting text

And finally, what was promised in the article on innovations in Android Marshmallow . Now you can add a menu to the menu that appears when you select text. The animated picture of this miracle was at the very beginning of the article, but if you want, it is again under the spoiler.

Implementation

To achieve this effect, you first need to create a callback inherited from ActionMode.Callback. That is, it is completely analogous to what we created in the two sections above for the “Contextual action mode” .

Further, for all elements in which we want to expand the menu when editing, you need to specify this callback:

 textView.setTextIsSelectable(true); textView.setCustomSelectionActionModeCallback(actionModeCallback); editText.setCustomSelectionActionModeCallback(actionModeCallback); editText.setCustomInsertionActionModeCallback(actionModeCallback); 

The callback specified in setCustomSelectionActionModeCallback () will be used if there is selected text. Specified in setCustomInsertionActionModeCallback () - if there is no text. Separated them because not all actions make sense when nothing is selected, and, accordingly, the contents of the appearing menu should be different.

On an empty EditText it looks like this:

Oh. Where did my menu go?

Look at the screenshots below. Any idea where all the added menu items are?

A hint can be found here:



I will explain. It is likely that the remaining items will not fit in the second, vertical part of the menu either. And there will be a scroll. In the screenshots above it happened.

The problem is that the user doesn’t see any signs of scrolling: the scrolling icon disappears almost immediately, and the edge of the unclaimed item doesn’t look. I got the bug, let's see what the creators of this feature say. code.google.com/p/android/issues/detail?id=195043

Where did my menu go again?

This time there is another problem: the menu does not expand with fullscreen input mode as described above. I found only one workout: turn off fullscreen mode using android: imeOptions = "flagNoExtractUi".

How to place your item before the standard?

Native menu items have order parameters from 1 to 5. Therefore, using the android: orderInCategory in the menu description, you cannot set the position before the native items. But you can change the order of items in the already formed menu, for example, like this:

 @Override public boolean onPrepareActionMode(ActionMode mode, Menu menu) { //    ""  1, //   ""  100 while (menu.getItem(0).getOrder() < 100) { MenuItem item = menu.getItem(0); menu.removeItem(item.getItemId()); //    ""  200,   //    menu.add(item.getGroupId(), item.getItemId(), item.getOrder() + 200, item.getTitle()); } return true; } 

We get the result:

Oddities in the documentation

There is no normal documentation for expanding the menu when selecting text. There is an article already mentioned, an article about Android Marshmallow updates .

I reread this place several dozen times, but I could not relate what is written there to practice. I tell in order.



If you read this article or tried it yourself, you noticed that startActionMode (callback, ActionMode.TYPE_FLOATING) does create a floating toolbar, but not at all for selection. And for selection it creates setCustomSelectionActionModeCallback () .



The second incomprehensible instruction. The setCustomSelectionActionModeCallback () method of the android.widget.TextView class expects to receive an ActionMode.Callback .



android.googlesource.com/platform/frameworks/base/+/master/core/java/android/widget/TextView.java

If you look at android.widget.Editor , then the mCustomSelectionActionModeCallback field is also of type ActionMode.Callback :



And nowhere in this code is it expected that custom callback will be of type ActionMode.Callback2 .
android.googlesource.com/platform/frameworks/base/+/master/core/java/android/widget/Editor.java

The article continues to talk hard about how to use ActionMode.Callback2 :



My guess is that a fragment of some internal documentation on ActionMode.Callback2 got into the article due to an editor's oversight. Do you have any other hypothesis, write about it.

Example

The entire code from this article can be found on GitHub .