EditText : Inserting a tab character

Question

As part of my application, I have simple screen for entering text. When the focus is in the EditText, it never receives the tab character.

I press on the tab key on the virtual keyboard, but the behaviour is that the keyboard disappears.

Here is my layout :

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginLeft="10dp"
        android:layout_marginRight="10dp"
        android:orientation="vertical" >

        <TextView
            android:id="@+id/textView1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Intitulé"
            android:textAppearance="?android:attr/textAppearanceMedium" />

    <EditText
        android:id="@+id/etTextTitle"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginLeft="15dp"
        android:inputType="textCapSentences"
        android:singleLine="true"
        android:imeOptions="actionNext" >

        <requestFocus />
    </EditText>

    <TextView
        android:id="@+id/tvContent"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Contenu"
        android:textAppearance="?android:attr/textAppearanceMedium" />

    <EditText
        android:id="@+id/etText"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="left|top"
        android:layout_marginLeft="15dp"
        android:textSize="25sp"
        android:lineSpacingExtra="4dp"
        android:singleLine="false"
        android:inputType="textMultiLine"
        android:scrollHorizontally="false"
        android:scrollbarStyle="insideOverlay"
        android:scrollbars="vertical"
        android:overScrollMode="always" />

</LinearLayout>

The control in question is the last EditText, as it is multiline, with scrolling.

I need to provide this so that the user can do some (very) basic formatting.

Any ideas ?

Check out : http://stackoverflow.com/questions/17989733/move-to-another-edittext-when-soft-keyboard-next-is-clicked-on-android — Haresh Chhelana, May 05 '15 at 12:08
You seem to have misunderstood. I want to be able to add the tab character to the text content, not jump to the next field. — Simon, May 05 '15 at 16:07

johnkarka · Answer 1 · 2015-05-25T16:53:29.767

According to your comment, "tab" character is not much different from "space" character. So workaround should be enlarging tab width.

Here is the working code.

tab width = INDEX_CHAR * TAB_NUMBER

Search every TAB character in the string and apply it the custom ReplacementSpan , with getSize() returning tab width.

private static final String INDEX_CHAR="m";
private static final int TAB_NUMBER = 3;
public void applyTabWidth(Editable text, int start, int end)    {
    String str=text.toString();
    float tabWidth=getPaint().measureText(INDEX_CHAR) * TAB_NUMBER;     
    while (start < end)     {
        int index=str.indexOf("\t",start);
        if(index<0)
            break;
        text.setSpan(new CustomTabWidthSpan(Float.valueOf(tabWidth).intValue()) , index, index+1, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
        start = index+1;
    }
}

CustomTabWidthSpan

class CustomTabWidthSpan extends ReplacementSpan
{
    int tabWidth=0;
    CustomTabWidthSpan(int tabWidth){
        this.tabWidth=tabWidth;
    }
    @Override
    public int getSize(Paint p1, CharSequence p2, int p3, int p4, Paint.FontMetricsInt p5)
    {
        return tabWidth;
    }

    @Override
    public void draw(Canvas p1, CharSequence p2, int p3, int p4, float p5, int p6, int p7, int p8, Paint p9)
    {           
    }
}

Optimization:

I choose not to apply ReplacementSpan to the whole string but only to each TAB character.

Everytime text has been changed, search TAB characters only in changed text. Below is how to apply TextWacher.

editText.addTextChangedListener(new TextWatcher(){
    int start=0,end=0;
        @Override
        public void beforeTextChanged(CharSequence p1, int p2, int p3, int p4)
        {
        }

        @Override
        public void onTextChanged(CharSequence p1, int start, int before, int count)
        {
            this.start=start;
            this.end=start+count;
        }

        @Override
        public void afterTextChanged(Editable p1)
        {
            applyTabWidth(p1, start, end);
        }
    });

@Croutonix I'm glad that I help someone ;) – johnkarka Oct 24 '16 at 01:59 — johnkarka, Oct 24 '16 at 01:59

score 1 · Answer 2 · answered May 20 '15 at 11:39

Which virtual keyboard did you use? I thought stock keyboards do not contain "TAB" character.

If you use third-party keyboard, make sure if it enters real TAB character (ascii code - 61) or it simulate PC-like TAB behaviour (searching and focusing next EditText)

You should check like this.

@Override
public boolean onKeyUp(int keyCode, KeyEvent event)
{
    switch(keyCode){
        case KeyEvent.KEYCODE_TAB:
            Toast.makeText(this,"TAB key triggered!",Toast.LENGTH_SHORT).show();
            return true;
    }
    return super.onKeyUp(keyCode, event);
}

Note: I'm not answering your question,just giving a debug tip.

Hi @johnkarka, thanks for your answer. In fact I need to be able to import text files which hold tab characters and then display them correctly. On my Samsung Galaxy Tab Pro, the default softkeyboard has a tab key, which could mean I could capture it and then insert it into the edittext field. However, just to this point, it produces the same effect as a space character. — Simon, May 20 '15 at 15:19

EditText : Inserting a tab character

2 Answers2