Hatte ein ähnliches Problem, wollte aber eine Mitte ohne Text und ohne umbrochene Layouts zeichnen. Die Lösung bestand darin, eine benutzerdefinierte Schaltfläche zu erstellen und zusätzlich zu LINKS, RECHTS, OBEN und UNTEN eine weitere Zeichenfläche hinzuzufügen. Man kann die zeichnbare Platzierung leicht ändern und sie in der gewünschten Position relativ zum Text haben.
CenterDrawableButton.java
public class CenterDrawableButton extends Button {
private Drawable mDrawableCenter;
public CenterDrawableButton(Context context) {
super(context);
init(context, null);
}
public CenterDrawableButton(Context context, AttributeSet attrs) {
super(context, attrs);
init(context, attrs);
}
public CenterDrawableButton(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init(context, attrs);
}
@TargetApi(Build.VERSION_CODES.LOLLIPOP)
public CenterDrawableButton(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
super(context, attrs, defStyleAttr, defStyleRes);
init(context, attrs);
}
private void init(Context context, AttributeSet attrs){
//if (isInEditMode()) return;
if(attrs!=null){
TypedArray a = context.getTheme().obtainStyledAttributes(
attrs, R.styleable.CenterDrawableButton, 0, 0);
try {
setCenterDrawable(a.getDrawable(R.styleable.CenterDrawableButton_drawableCenter));
} finally {
a.recycle();
}
}
}
public void setCenterDrawable(int center) {
if(center==0){
setCenterDrawable(null);
}else
setCenterDrawable(getContext().getResources().getDrawable(center));
}
public void setCenterDrawable(@Nullable Drawable center) {
int[] state;
state = getDrawableState();
if (center != null) {
center.setState(state);
center.setBounds(0, 0, center.getIntrinsicWidth(), center.getIntrinsicHeight());
center.setCallback(this);
}
mDrawableCenter = center;
invalidate();
requestLayout();
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
if(mDrawableCenter!=null) {
setMeasuredDimension(Math.max(getMeasuredWidth(), mDrawableCenter.getIntrinsicWidth()),
Math.max(getMeasuredHeight(), mDrawableCenter.getIntrinsicHeight()));
}
}
@Override
protected void drawableStateChanged() {
super.drawableStateChanged();
if (mDrawableCenter != null) {
int[] state = getDrawableState();
mDrawableCenter.setState(state);
mDrawableCenter.setBounds(0, 0, mDrawableCenter.getIntrinsicWidth(),
mDrawableCenter.getIntrinsicHeight());
}
invalidate();
}
@Override
protected void onDraw(@NonNull Canvas canvas) {
super.onDraw(canvas);
if (mDrawableCenter != null) {
Rect rect = mDrawableCenter.getBounds();
canvas.save();
canvas.translate(getWidth() / 2 - rect.right / 2, getHeight() / 2 - rect.bottom / 2);
mDrawableCenter.draw(canvas);
canvas.restore();
}
}
}
attrs.xml
<resources>
<attr name="drawableCenter" format="reference"/>
<declare-styleable name="CenterDrawableButton">
<attr name="drawableCenter"/>
</declare-styleable>
</resources>
Verwendung
<com.virtoos.android.view.custom.CenterDrawableButton
android:id="@id/centerDrawableButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:drawableCenter="@android:drawable/ic_menu_info_details"/>