Double click listener android

как реализовать двойной клик в Андроид

Я делаю проект, в котором я хочу отобразить конкретное сообщение на одно касание и другое сообщение на двойное касание с помощью android.Как я могу его реализовать.

мой пример кода ниже

7 ответов

Почему бы вам не использовать длительное нажатие события insted в то время как его рекомендуемый пользовательский интерфейс. Читать Ответ Тут , я настоятельно рекомендую использовать это.

или если его так или иначе вы хотите реализовать, у вас есть два варианта, один из них это с помощью boolean а во-вторых, использует Жест Слушателя.

попробуйте использовать GestureDetector .

вы можете использовать при длинном щелчке вместо двойного щелчка, переопределив этот метод

вызывается при щелчке и удержании представления.

это удержание, но для новых читателей я сделал небольшую библиотеку для упрощения такого рода вещей, проверьте эту статью: дважды щелкните прослушиватель на android.

библиотека очень маленькая, а вот Ссылка На Репозиторий GitHub.

и вы просто будете использовать его так:

попробуйте следующий измененный код::

я реализовал код, на котором цвет фона и цвет текста изменяется при нажатии на экран дважды (двойное нажатие) вот код.

можно использовать RxAndroid в таком случае в Котлине должно быть так:

1. применить clicks() функция расширения на данном представлении, которая создает наблюдаемую последовательность RX.
2. мы говорим RX, чтобы сгенерировать событие. после 500 мс или 2 последовательных кликов проходить в течение 500 мс.
3. мы говорим RX принимать только события только с 2 последовательных щелчка
4. последнее, но не менее важное: мы подписываемся на последовательность событий который является нашим обработчиком DoubleClick

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Как поймать события двойного нажатия в Android с помощью OnTouchListener

Я пытаюсь поймать события двойного нажатия с помощью OnTouchListener. Я думаю, что я бы установил long для motionEvent.ACTION_DOWN, и другой длинный для второго motionEvent.ACTION_DOWN и измерить время между ними двумя, а затем сделать что-то с ним. Тем не менее, мне трудно понять, как именно подойти к этому. Я использую случаи переключения, чтобы забрать мультитач-события, поэтому я бы предпочел не пытаться перепробовать все это, чтобы реализовать GestureDetector (и, к сожалению, это невозможно реализовать как ontouchlistener, так и Gesturedetector одновременно). Любые идеи очень помогли бы:

6 ответов

Я рассматривал эту проблему ранее. Он включает в себя использование обработчика для ожидания определенного количества времени для ожидания второго щелчка:Как создать событие с одним щелчком мыши и событие с двойным щелчком при нажатии кнопки Меню?

в определении класса:

с вспомогательным классом SimpleGestureListener, который реализует GestureListener и OnDoubleTapListener, вам не нужно много делать.

Это много easyer:

вот мое решение.

для меня было важно иметь быстрое и четкое разделение «одного крана» и «двойного крана». Я пытался!—2—> первый, но имел очень плохие результаты. Может быть, результат моего вложенного использования scrollviews-кто знает.

я фокусируюсь на MotionEvent.ACTION_UP и идентификатор резьбового элемента. Чтобы сохранить первый кран живым, я использую Handler отправка отложенного сообщения (350ms), так что у пользователя есть некоторое время, чтобы разместить свой второй кран на ImageView . Если пользователь разместил второй нажмите на элемент с идентичным идентификатором я принимаю это как двойное нажатие, удалите отложенное сообщение и запустите мой пользовательский код для «двойного нажатия». Если пользователь разместил кран на элементе с другим идентификатором, я беру это как новый кран и создаю другой Handler для него.

глобальные переменные класса

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Basic Event Listeners

Event Listening in Android development is largely centered around the View object.

Any View (Button, TextView, etc) has many event listeners that can be attached using the setOnEvent pattern which involves passing a class that implements a particular event interface. The listeners available to any View include:

• setOnClickListener — Callback when the view is clicked
• setOnDragListener — Callback when the view is dragged
• setOnFocusChangeListener — Callback when the view changes focus
• setOnGenericMotionListener — Callback for arbitrary gestures
• setOnHoverListener — Callback for hovering over the view
• setOnKeyListener — Callback for pressing a hardware key when view has focus
• setOnLongClickListener — Callback for pressing and holding a view
• setOnTouchListener — Callback for touching down or up on a view

Using Java

In Java Code, attaching to any event works roughly the same way. Let’s take the OnClickListener as an example. First, you need a reference to the view and then you need to use the set method associated with that listener and pass in a class implementing a particular interface. For example:

Alternatively, it is sometimes useful to have your class implement the listener directly, in which case you would add the listener implementation to your class and pass a reference to your class to the set method. For Example:

This pattern works for any of the view-based event listeners.

Using XML

In addition onClick has a unique shortcut that allows the method to specified within the layout XML. So rather than attaching the event manually in the Java, the method can be attached in the view. For example:

Within the Activity that hosts this layout, the following method handles the click event:

In addition to the standard View listeners, AdapterView descendants have a few more key event listeners having to do with their items:

• setOnItemClickListener — Callback when an item contained is clicked
• setOnItemLongClickListener — Callback when an item contained is clicked and held
• setOnItemSelectedListener — Callback when an item is selected

This works similarly to a standard listener, simply implementing the correct AdapterView.OnItemClickListener interface:

This works similarly for the setting up a «long click» where an item is pressed and held down using the OnItemLongClickListener:

Troubleshooting: Item Click Not Firing If the item is more complex and does not seem to be properly responding to clicks after setting up the handler, the views inside the item might be drawing the focus. Check out this stackoverflow post and add the property android:descendantFocusability=»blocksDescendants» to the root layout within the template for the item.

In addition to the listeners described above, there are a few other common listeners for input fields in particular.

• addTextChangedListener — Fires each time the text in the field is being changed
• setOnEditorActionListener — Fires when an «action» button on the soft keyboard is pressed

If you want to handle an event as the text in the view is being changed, you only need to look as far as the addTextChangedListener method on an EditText (or even TextView):

This is great for any time you want to have the UI update as the user enters text.

Another case is when you want an action to occur once the user has finished typing text with the Soft Keyboard. Keep in mind that this is especially useful when you can see the virtual keyboard which is disabled by default in the emulator but can be enabled as explained in this graphic.

First, we need to setup an «action» button for our text field. To setup an «action button» such as a Done button on the soft Keyboard, simply configure your EditText with the following properties:

In particular, singleLine and imeOptions are required for the Done button to display. Now, we can hook into a editor listener for when the done button is pressed with:

This is often great whenever a user needs to type text and then explicitly have an action performed when they are finished. There are many imeOptions for different situations.

Similarly to EditText, many common input views have listeners of their own including NumberPicker has setOnValueChangedListener and SeekBar has setOnSeekBarChangeListener which allow us to listen for changes:

Almost all input views have similar methods available.

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Android Accessibility — Resolving common Talkback issues

Many Android applications suffer from similar Talkback issues and at Microsoft To Do we run into these often as well. We use multiple strategies to make our app more accessible. This article covers a few scenarios where Talkback experience is improved.

A companion Github repository containing the sample code is available here. You can check it out and try running the demo app on your device to experience the issues and try the solutions yourself.

Combining views into groups

Not everything visible on the screen is meaningful; some views are used only for decoration, some images illustrate the text without adding additional information, and sometimes multiple views convey the meaning together but do not make sense separately. In these cases, the views can be combined to allow Talkback user to quickly navigate entire view, rather than having to skip through multiple different elements.

Example

Talkback reads the user element on the page as “User placeholder avatar”, “Name”, and then “Surname”. Each element can be navigated individually. The user icon is a placeholder which does not provide additional information. It takes three swipes to navigate through the element.

Solution

Content description is set on the entire group so Talkback reads only one label, containing all user information as “Name Surname”. Now navigation is done in only one swipe.

XML layout snippet

Content description is set on LinearLayout, child views are marked as not important for accessibility individually.

Action descriptions

As Talkback navigates the elements with click actions, the announcement generated will include some information, for example “Login, Button, Double tap to activate”. However, relying on default announcements is not always enough.

Example

A button with two actions generates an accessibility announcement of “Edit note, Double tap to activate, Double tap and hold to long press”.

Solution

Actions are modified to announce “Double tap to edit note, Double tap and hold to copy note”.

Code snippet

Custom actions are added in accessibility delegate, ensuring that it’s clear what happens when each action is carried out.

Roles

Talkback reads the element roles, such as Button, Switch, Checkbox, etc. This gets complicated when non-standard elements are used. For example, adding a click listener will add an action to Talkback announcement, but the role will generally not change, potentially causing confusion.

Example

The button is announced as “Login, Button”. Adding on a click listener to TextView does not include the “Button” announcement. In the last example, TextView is announced as “Button”.

Code snippet

Role is added by including it in the accessibility delegate. This is not an ideal solution; best practice is to use elements as intended, so using Button when Button behaviour is needed, which avoids the need to modify roles manually, as it is easy to miss some behaviour which comes by default. However, in some cases, this will help.

Updating information after state changes

Lint warning often reminds us about adding initial content descriptions, but for the elements with states, this might not be enough. It is important to remember to update accessibility information as well.

Example

The favorite button is not updated after the user taps on it, so the Talkback announcement still reads “Not favorite item, Button, Double tap to activate” after the user already added the item to favorites and the UI is updated to reflect this.

Solution

Favorite button content and action descriptions are updated so Talkback reads one of two states: “Not favorite item, Button, Double tap to add to favorites” and “Favorite item, Button, Double-tap to remove from favorites”.

Code snippet

When a tap event is received and the element state changes, the content and action descriptions are updated to reflect the current state of the item. This is especially important for elements which represent On/Off state, like the favorite button. Alternatively, an element which already supports On/Off states could be used in this scenario, like Switch or Checkbox. On the other hand, if more than two states are available, then custom elements make sense.

RecyclerView scrolling

If RecyclerView does not automatically scroll with Talkback navigation, it will make it very hard for Talkback users to know that there are more elements available. There is one common issue which usually causes this.

Example

The first RecyclerView allows user to see the first 5 elements and then navigation skips the rest. The second RecyclerView moves to the 6th element in the list and scrolls down to make additional elements available. The focus only moves away from RecyclerView when all elements are visited.

Layout snippet

If the following line is in the RecyclerView layout, removing it will fix the issue. It will also add additional in/out of list announcements to help the users navigate.

RecyclerView focus

As is the nature of RecyclerView, it can recycle the view holders if there are changes to the data. However, this can create focus issues if some view is no longer displayed or the view holder is reused in a different position. Understanding what is happening will help with keeping the focus unchanged.

Example

RecyclerViews allow the user to mark elements as deleted. In the first RecyclerView, once the delete icon is tapped and the element text is replaced with “Deleted ”, the focus returns to the top of the activity, so the user needs to navigate through the entire screen again to return to the original focus position. The second RecyclerView keeps the focus on the same element, shifting it from the icon to the name.

Code snippet

After the element is marked as deleted there is a short delay to allow RecyclerView time to reuse ViewHolders, then the desired position is found and focus is returned to that position. If the underlying data set is not changed and there is no refresh of the data in RecyclerView adapter, this could potentially be solved within ViewHolder itself. As always, the best solution is the one which addresses the specific need.

Conclusions

Accessibility is important for our team at Microsoft To Do. We spend a lot of time making sure every user can stay organised and accomplish more, independent of how they use their device. Most of our Android app releases include several accessibility improvements. We also work with our design team to consider accessibility requirements from the start.

Accessibility issues we encounter range from simple to tricky — it takes time and dedication to find and resolve them all. I hope this article helps you to solve some. Code snippets in the article have been simplified for clarity, so check the sample code for full implementations.

Is there a different way you would approach some of these? Let’s discuss it!

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