Android properties in custom views

Question

I have a custom android view class which amongst other things is going to be drawing a lot of text directly into the canvas supplied to its onDraw override.

What I'd like to do is have a attribute which could be set to something like "?android:attr/textAppearanceLarge" and pick up the regular text settings without further styling.

In my custom view's attrs.xml, I have

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <declare-styleable name="MyView" >
        ...

        <attr name="textAppearance" format="reference" />

        ...
    </declare-styleable>
</resources>

and then in CustomView.java

final int[] bogus = new int[] { android.R.attr.textColor, android.R.attr.textSize, android.R.attr.typeface, android.R.attr.textStyle, android.R.attr.fontFamily };
final int ap = styledAttributes.getResourceId(com.test.R.styleable.MyView_textAppearance, -1);
final TypedArray textAppearance = ap != -1 ? context.obtainStyledAttributes(ap, bogus) : null;

if (textAppearance != null) {
    for (int i = 0; i < textAppearance.getIndexCount(); i++) {
        int attr = textAppearance.getIndex(i);

        switch (attr) {
        case android.R.attr.textColor:  textColor = textAppearance.getColor(attr, textColor); break;
        case android.R.attr.textSize:   textSize = textAppearance.getDimensionPixelSize(attr, textSize); break;
        case android.R.attr.typeface:   typefaceIndex = textAppearance.getInt(attr, typefaceIndex); break;
        case android.R.attr.textStyle:  textStyle = textAppearance.getInt(attr, textStyle);  break;
        case android.R.attr.fontFamily: fontFamily = textAppearance.getString(attr); break;         
        }
    }

    textAppearance.recycle();
}

I've tried all sorts of variations on the switch variable, on the case constants etc and I never end up getting anything even remotely useful.

What am I doing wrong here?

jampez77 · Accepted Answer · 2019-02-06 14:03:46Z

3

I know this is an old question but just stumbled into this issue and this solution works for me:

in attrs.xml

<resources>
    <declare-styleable name="CustomView">
        ....
        <attr name="textAppearance" format="reference" />
    </declare-styleable>
</resources>

in CustomView.java

textAppearance = a.getResourceId(R.styleable.CustomView_textAppearance, -1);
TextViewCompat.setTextAppearance(textView, textAppearance);

then in activity.xml

<CustomView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    app:textAppearance="?android:attr/textAppearanceMedium"

answered Feb 6, 2019 at 14:03

jampez77

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Comments

gompaq · Accepted Answer · 2016-08-10 07:54:22Z

I think you access to different resources:

com.test.R.styleable.MyView_textAppearance

is your own,

android.R.attr.textColor

and others are Android's.

So I managed to make it defining my own attributes:

    <com.test.TextView
        android:id="@+id/textView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        myns:textColor="@android:color/darker_gray" 
        myns:textSize="18sp"
        myns:textStyle="normal"/>

and attrs.xml:

<declare-styleable name="MyView_textAppearance">
    <attr name="textColor" format="reference|color" />

    <attr name="textSize" format="dimension" />
    <attr name="textStyle">
        <flag name="normal" value="0" />
        <flag name="bold" value="1" />
        <flag name="italic" value="2" />
    </attr>

</declare-styleable>

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