How do I create keypreview from InputMethodService using PopupWindow in android?

Question

I am trying to create custom keyboard for android system with Buttons and it is working fine. But now I want to add key preview. I am new in android, plese help me if it is possible showing popupwindow from InputMethodService.

Thank you in advance.

layout/key_preview.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="center">
    <TextView
        android:id="@+id/tvKeyPreview"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:textSize="30sp"
        android:gravity="center"
        android:text="1"
        android:textAlignment="center"
        android:textColor="@color/black"
        android:background="@color/white"/>

</RelativeLayout>

layout/number_key_pad.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_alignParentBottom="true"
    android:layout_marginLeft="20dp"
    android:layout_marginTop="5dp"
    android:layout_marginRight="20dp"
    android:layout_marginBottom="5dp"
    android:background="@color/teal_700">
    <!-- 789 -->
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center_horizontal"
        android:weightSum="4"
        android:orientation="horizontal"
        android:layout_marginTop="10dp">
        <Button style="@style/Button_Key_Style" android:id="@+id/Button7"  android:tag="55" android:text="7"  />
        <Button style="@style/Button_Key_Style" android:id="@+id/Button8"  android:tag="56" android:text="8" />
        <Button style="@style/Button_Key_Style" android:id="@+id/Button9"  android:tag="57" android:text="8" />
    </LinearLayout>
    <!-- 456 -->
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center_horizontal"
        android:weightSum="4"
        android:orientation="horizontal"
        android:layout_marginTop="10dp">
        <Button style="@style/Button_Key_Style" android:id="@+id/Button4"  android:tag="52" android:text="4"  />
        <Button style="@style/Button_Key_Style" android:id="@+id/Button5"  android:tag="53" android:text="5" />
        <Button style="@style/Button_Key_Style" android:id="@+id/Button6"  android:tag="54" android:text="6" />
    </LinearLayout>
    <!-- 123 -->
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center_horizontal"
        android:weightSum="4"
        android:orientation="horizontal"
        android:layout_marginTop="10dp">
        <Button style="@style/Button_Key_Style" android:id="@+id/Button1"  android:tag="49" android:text="1"  />
        <Button style="@style/Button_Key_Style" android:id="@+id/Button2"  android:tag="50" android:text="2" />
        <Button style="@style/Button_Key_Style" android:id="@+id/Button3"  android:tag="51" android:text="3" />
    </LinearLayout>
    <!-- ctr -->
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center_horizontal"
        android:weightSum="4"
        android:orientation="horizontal"
        android:layout_marginTop="10dp">
        <Button style="@style/Button_Key_Style" android:id="@+id/ButtonHash"  android:tag="55" android:text="#"  />
        <Button style="@style/Button_Key_Style" android:id="@+id/Button0"  android:tag="56" android:text="0" />
        <Button style="@style/Button_Key_Style" android:id="@+id/ButtonStrick"  android:tag="57" android:text="*" />
        <Button style="@style/Button_Key_Style" android:id="@+id/ButtonDelete"  android:tag="-1" android:text="\u232b" />
    </LinearLayout>

</LinearLayout>

import android.inputmethodservice.InputMethodService;
import android.view.Gravity;
import android.view.View;
import android.view.WindowManager;
import android.view.inputmethod.InputConnection;
import android.widget.Button;
import android.widget.PopupWindow;
import android.widget.TextView;

public class ButtonsKeyboard extends InputMethodService {
    final int KEY_CODE_DELETE = -1;
    View layout_KeyPad, layout_KeyPreview;
    PopupWindow keyPopup;
    @Override
    public View onCreateInputView() {
        layout_KeyPad = getLayoutInflater().inflate(R.layout.number_key_pad,null);
        layout_KeyPreview = getLayoutInflater().inflate(R.layout.key_preview,null);
        TextView tvkeyPreiew = layout_KeyPreview.findViewById(R.id.tvKeyPreview);
        Button button1 = layout_KeyPad.findViewById(R.id.Button1);
        Button button2 = layout_KeyPad.findViewById(R.id.Button2);
        Button button3 = layout_KeyPad.findViewById(R.id.Button3);
        Button buttonDelete = layout_KeyPad.findViewById(R.id.ButtonDelete);
        keyPopup = new PopupWindow(getApplicationContext());
        button1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                int keyCode = Integer.parseInt(v.getTag().toString());
                if(keyCode>0){
                    tvkeyPreiew.setText(button1.getText());
                    keyPopup.setContentView(layout_KeyPreview);
                    keyPopup.setWidth(button1.getWidth()+4);
                    keyPopup.setHeight(button1.getHeight()+4);
                    int x = (int)button1.getX() -4;
                    int y = (int)button1.getY() -10;
                    keyPopup.showAtLocation(button1, Gravity.NO_GRAVITY,x,y);
                    writeText(keyCode);
                }
            }
        });
        button2.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                int keyCode = Integer.parseInt(v.getTag().toString());
                if(keyCode>0){
                    tvkeyPreiew.setText(button2.getText());
                    keyPopup.setContentView(layout_KeyPreview);
                    keyPopup.setWidth(button2.getWidth()+4);
                    keyPopup.setHeight(button2.getHeight()+4);
                    int x = (int)button2.getX() -4;
                    int y = (int)button2.getY() -10;
                    keyPopup.showAtLocation(button2, Gravity.NO_GRAVITY,x,y);
                    writeText(keyCode);
                }
            }
        });
        button3.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                int keyCode = Integer.parseInt(v.getTag().toString());
                if(keyCode>0){
                    tvkeyPreiew.setText(button3.getText());
                    keyPopup.setContentView(layout_KeyPreview);
                    keyPopup.setWidth(button3.getWidth()+4);
                    keyPopup.setHeight(button3.getHeight()+4);
                    int x = (int)button3.getX() -4;
                    int y = (int)button3.getY() -10;
                    keyPopup.showAtLocation(button3, Gravity.NO_GRAVITY,x,y);
                    writeText(keyCode);
                }
            }
        });
        buttonDelete.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                InputConnection ic = getCurrentInputConnection();
                ic.deleteSurroundingText(1,0);
            }
        });
        return layout_KeyPad;
    }
    private void writeText(int keyCode){
        InputConnection ic = getCurrentInputConnection();
        if(ic == null) return;
        char code = (char) keyCode;
        ic.commitText(String.valueOf(code),1);
        keyPopup.dismiss();
    }
}

I is working but no popupwindow is displayed.

Answer 1

You can Add Popup View in Kotlin Like this.

private fun showSortPopup() {


        val sortBinding = PopupSortTaskBinding.inflate(layoutInflater)
        val popup = PopupWindow(
            sortBinding.root, 300.toPx().toInt(), // popup width = 300dp converted tp pixels
            LayoutParams.WRAP_CONTENT
        )
        popup.isFocusable = true
        popup.isOutsideTouchable = true
        popup.elevation = 30f
        sortBinding.rcvSort.adapter = SortTaskAdapter(sortTypes, selectedSortType) {
            selectedSortType = it
            todoTaskList = todoTaskList.sortTasks()
            todoAdapter.submitList(todoTaskList.filterListBySite(), userId)
            binding.layoutHome.rcvTasks.smoothScrollToPosition(0)
            popup.dismiss()
        }

        sortBinding.rcvSort.setDivider()
        val xOff = -270.toPx().toInt()//width = 300 - 30 padding
        popup.showAsDropDown(binding.layoutHome.imgSort, xOff, -12.toPx().toInt())
    }

Here popup.showAsDropDown will open the popup which you want to show on view.