android - Cursor control in EditText

Question

Ok, this is about to drive me nuts. I'm still a newbie (and maybe an idiot) but this one has had me running in circles.

I'm trying to implement cursor control in an editText via soft buttons (left, right, up down). From what I've researched, it looks like I need the methods in the Selection object like moveUp(), moveLeft(), extendUp() etc. but they all need a "text.layout" object and I don't know how to get one.

Am I on the right track? Help?

Answer 1

A simple example for moving the text cursor:

package connect1.de;


import android.app.Activity;
import android.os.Bundle;


import android.text.Editable;
import android.text.method.KeyListener;
import android.util.Log;
import android.view.View;
import android.view.inputmethod.BaseInputConnection;
import android.view.inputmethod.CompletionInfo;
import android.view.inputmethod.ExtractedText;
import android.view.inputmethod.ExtractedTextRequest;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.view.View.OnClickListener;


public class Connection1 extends Activity implements OnClickListener
{
    /** Called when the activity is first created. */

    private  EditText s1 = null;
    private  EditText s2 = null;
    Button button1;
    Button button2;
    private  EditableInputConnection in;
    private test1 t1;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        // dieser Aufruf funktioniert nicht !!
        // in = new  EditableInputConnection(s1);

        setContentView(R.layout.main);
        // so hunktioniert der Aufruf ohne Absturz
        s1 = (EditText) findViewById(R.id.editText1);
        // s2 = (EditText) findViewById(R.id.editText2);
        s1.setText("Test Button");
        button1 = (Button) findViewById(R.id.button1);
        button2 = (Button) findViewById(R.id.button2);
        // t1 = new test1(s1);
        in = new  EditableInputConnection(s1);

        // dies bewirkt ein absolutes Verschieben des Textcursors auf Position 10 - 1, 1 zeigt ans Ende der Eingabe
        // in.commitText("", 5);
        // in = new  EditableInputConnection(s1);
        // in.commitText("", 7);
        button1.setOnClickListener(this);
        button2.setOnClickListener(this);
        // in.cursor_pos();
    }

    /*
     * Copyright (C) 2007-2008 The Android Open Source Project
     * 
     * Licensed under the Apache License, Version 2.0 (the "License"); you may not
     * use this file except in compliance with the License. You may obtain a copy of
     * the License at
     * 
     * http://www.apache.org/licenses/LICENSE-2.0
     * 
     * Unless required by applicable law or agreed to in writing, software
     * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
     * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
     * License for the specific language governing permissions and limitations under
     * the License.
     */


    /*
     * Copyright (C) 2007-2008 The Android Open Source Project
     * 
     * Licensed under the Apache License, Version 2.0 (the "License"); you may not
     * use this file except in compliance with the License. You may obtain a copy of
     * the License at
     * 
     * http://www.apache.org/licenses/LICENSE-2.0
     * 
     * Unless required by applicable law or agreed to in writing, software
     * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
     * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
     * License for the specific language governing permissions and limitations under
     * the License.
     */
     public void onClick(View v) 
     {
         int pos = 0;
         pos = in.cursor_pos();
         // wie k?nnen die verschiedenen Schaltfl?chen unterschieden werden
         if (v.findViewById(R.id.button2) == findViewById(R.id.button2))
           // s1.setText(v.findViewById(R.id.button2) + "");
           pos = pos + 2;
         // else
           // s1.setText("Linke Taste gedrückt");

         // für links
         // in.commitText("", pos);
         // -1 hat auch Wirkung für Linksschritt
         in.commitText("", pos );

     }


    public class test1
    {
          private final TextView mTextView;

          public test1(TextView textview)
          {
              mTextView = textview;
              mTextView.setText("Klasse 1");
          }
    }
    public class EditableInputConnection extends BaseInputConnection 
    {
        private static final boolean DEBUG = false;
        private static final String TAG = "EditableInputConnection";

        private final TextView mTextView;

        public EditableInputConnection(TextView textview) 
        {
            super(textview, true);
            mTextView = textview;
            // mTextView.setText("Inputconnection");
        }

        public Editable getEditable() 
        {
            TextView tv = mTextView;
            if (tv != null) 
            {
                return tv.getEditableText();
            }
            return null;
        }

        public boolean beginBatchEdit() 
        {
            mTextView.beginBatchEdit();
            return true;
        }

        public boolean endBatchEdit() 
        {
            mTextView.endBatchEdit();
            return true;
        }

        public boolean clearMetaKeyStates(int states) 
        {
            final Editable content = getEditable();
            if (content == null) return false;
            KeyListener kl = mTextView.getKeyListener();
            if (kl != null) {
                try {
                    kl.clearMetaKeyState(mTextView, content, states);
                } catch (AbstractMethodError e) {
                    // This is an old listener that doesn't implement the
                    // new method.
                }
            }
            return true;
        }

        public boolean commitCompletion(CompletionInfo text) 
        {
            if (DEBUG) Log.v(TAG, "commitCompletion " + text);
            mTextView.beginBatchEdit();
            mTextView.onCommitCompletion(text);
            mTextView.endBatchEdit();
            return true;
        }

        public boolean performEditorAction(int actionCode) 
        {
            if (DEBUG) Log.v(TAG, "performEditorAction " + actionCode);
            mTextView.onEditorAction(actionCode);
            return true;
        }

        public boolean performContextMenuAction(int id) 
        {
            if (DEBUG) Log.v(TAG, "performContextMenuAction " + id);
            mTextView.beginBatchEdit();
            mTextView.onTextContextMenuItem(id);
            mTextView.endBatchEdit();
            return true;
        }
        public int cursor_pos()
        {
            int anzahl = 0;
            CharSequence str ;
            str = super.getTextBeforeCursor(s1.length(), 0);
            // s2.setText(str.length()+ "");
            anzahl = str.length();
            return anzahl;
        }
        public ExtractedText getExtractedText(ExtractedTextRequest request, int flags) 
        {
            if (mTextView != null) 
            {
                ExtractedText et = new ExtractedText();
                if (mTextView.extractText(request, et)) {
                    if ((flags&GET_EXTRACTED_TEXT_MONITOR) != 0)
                     {
                        // dieser Aufruf funktioniert nicht !!
                        // mTextView.setExtracting(request);
                    }
                    return et;
                }
            }
            return null;
        }

        public boolean performPrivateCommand(String action, Bundle data) 
        {
            mTextView.onPrivateIMECommand(action, data);
            return true;
        }

        @Override
        public boolean commitText(CharSequence text, int newCursorPosition) 
        {
            // notwendig, da sonst Eingabetext für Inputmethode nicht aktualisiert wird!!
            mTextView.setText(s1.getText());
            if (mTextView == null) 
            {
                return super.commitText(text, newCursorPosition);
            }
            CharSequence errorBefore = mTextView.getError();
            // mTextView.setText("");

            boolean success = super.commitText(text, newCursorPosition);
            CharSequence errorAfter = mTextView.getError();

            if (errorAfter != null && errorBefore == errorAfter) 
            {
                mTextView.setError(null, null);
            }

            // s2.setText(newCursorPosition + "");
            return success;

        }
    }

}