Quickly implement Android input method!

Codewords work hard! Please indicate the source!

0. Preface

I am working on a remote terminal recently, and I need to input text remotely, but because of network transmission, it often happens that the click becomes a long press, double click, etc...

So the product put forward a demand to make a remote input method. I thought about Android for ten years, and the mere input method should have already grabbed the data.

——Unexpectedly , I did not expect that the official Android input method documents were written sparsely , and the relevant information was copied from the official documents , which was useless at all! ! !

Angrily, I decided to write a real document by myself, huh!

1. Create a service

First create a class that inherits InputMethodService

public class FastInputIME extends InputMethodService{

}

Then declare the service

<service android:name="FastInputIME"
            android:label="牛逼哄哄的输入法"
            android:permission="android.permission.BIND_INPUT_METHOD">
            <intent-filter>
                <action android:name="android.view.InputMethod" />
            </intent-filter>
            <meta-data android:name="android.view.im"
                android:resource="@xml/method" />
</service>

Finally, use the universal key (Alt+Enter) to create the missing @xml/method file and write the following

<?xml version="1.0" encoding="utf-8"?>
<input-method xmlns:android="http://schemas.android.com/apk/res/android"
    android:settingsActivity="com.package.SettingsActivity"
    android:supportsSwitchingToNextInputMethod="true">
</input-method>

At this point, you can already see the awesome input method in the settings:

2. Create a keyboard layout

To make it easy to read, write a very, very simple numeric keyboard. Note that the label name is Keyboard , not KeyboardView in the syntax prompt:

<?xml version="1.0" encoding="utf-8"?>
<Keyboard xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <Row>
        <Key android:codes="1" android:keyLabel="1" />
        <Key android:codes="2" android:keyLabel="2" />
        <Key android:codes="3" android:keyLabel="3" />
        <Key android:codes="4" android:keyLabel="4" />
        <Key android:codes="5" android:keyLabel="5" />
        <Key android:codes="6" android:keyLabel="6" />
        <Key android:codes="7" android:keyLabel="7" />
        <Key android:codes="8" android:keyLabel="8" />
        <Key android:codes="9" android:keyLabel="9" />
        <Key android:codes="0" android:keyLabel="0" />
    </Row>
</Keyboard>

Among them, keyLabel is the text displayed on the button, and codes is the keycode to be used for monitoring in a while~

3. Create callbacks, bind keyboards, and add input events

Because it is very simple, you can just look at the part where I wrote the comment~

package com.eternity.lab;

import android.inputmethodservice.InputMethodService;
import android.inputmethodservice.Keyboard;
import android.inputmethodservice.KeyboardView;
import android.view.View;
import android.view.inputmethod.EditorInfo;
import android.view.inputmethod.InputConnection;

public class FastInputIME extends InputMethodService implements KeyboardView.OnKeyboardActionListener {

    private InputConnection ic;

    @Override
    public View onCreateInputView() {
        KeyboardView keyboardView = new KeyboardView(getApplicationContext(), null);

        //在此处导入键盘布局
        Keyboard keyboard = new Keyboard(getApplicationContext(), R.layout.keyboard);
        keyboardView.setKeyboard(keyboard);
        keyboardView.setOnKeyboardActionListener(this);
        return keyboardView;
    }

    @Override
    public void onWindowShown() {
        super.onWindowShown();

        /** 进入此回调时，用户将开始输入
            在此时保存InputConnection，用于后续的输入操作 **/
        ic = getCurrentInputConnection();
    }

    @Override
    public void onWindowHidden() {
        super.onWindowHidden();
        /** 进入此回调时，用户已结束输入
            在此时清理InputConnection **/
        ic = null;
    }

    @Override
    public void onPress(int primaryCode) {

        /** 此处的primaryCode，即键盘布局中的code属性，可以根据code来commit需要输入的文字
            第二个参数是输入的位置，注意是从右往左，0代表向右边插入一个字符 **/
        ic.commitText("" + primaryCode, 0);
    }

    @Override
    public void onRelease(int primaryCode) {
    }

    @Override
    public void onKey(int primaryCode, int[] keyCodes) {
    }

    @Override
    public void onText(CharSequence text) {
    }

    @Override
    public void swipeLeft() {
    }

    @Override
    public void swipeRight() {
    }

    @Override
    public void swipeDown() {
    }

    @Override
    public void swipeUp() {
    }
}

At this point, a simple custom input method is complete~

The remaining complex functions can be realized one by one in the documentation:

https://developer.android.google.cn/guide/topics/text/creating-input-method

Finally, it is customary to ask for money: