I have three files. The XML, the draw function and the main Activity.
I have some LinearLayout
in my XML file.
<LinearLayout android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1">
<LinearLayout android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1"
android:background="#ef3"
android:id="@+id/img01"/>
<LinearLayout android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1"
android:background="#E8A2B4"
android:id="@+id/img02"/>
</LinearLayout>
This is the draw function:
public class getBorder extends TextView {
public getBorder(Context context) {
super(context);
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
Paint paint = new Paint();
paint.setColor(android.graphics.Color.RED);
canvas.drawLine(0, 0, this.getWidth() - 1, 0, paint);
canvas.drawLine(0, 0, 0, this.getHeight() - 1, paint);
canvas.drawLine(this.getWidth() - 1, 0, this.getWidth() - 1,
this.getHeight() - 1, paint);
canvas.drawLine(0, this.getHeight() - 1, this.getWidth() - 1,
this.getHeight() - 1, paint);
}
}
And this is the main Activity:
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
final getBorder getBorder = new getBorder(this);
final LinearLayout img01 = (LinearLayout) findViewById(R.id.img01);
img01.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
getBorder.setWidth(100);
getBorder.setHeight(100);
img01.addView(getBorder);
}
});
}
The program could draw border but the size doesn't fit the LinearLayout
. And when I click the LinearLayout
again, the program crashed.
Also, I want to draw two circles in the center of the LinearLayout
, but how could I figure out the center coordinates?
This question is related to
android
android-layout
draw
Extend LinearLayout/RelativeLayout and use it straight on the XML
package com.pkg_name ;
...imports...
public class LinearLayoutOutlined extends LinearLayout {
Paint paint;
public LinearLayoutOutlined(Context context) {
super(context);
// TODO Auto-generated constructor stub
setWillNotDraw(false) ;
paint = new Paint();
}
public LinearLayoutOutlined(Context context, AttributeSet attrs) {
super(context, attrs);
// TODO Auto-generated constructor stub
setWillNotDraw(false) ;
paint = new Paint();
}
@Override
protected void onDraw(Canvas canvas) {
/*
Paint fillPaint = paint;
fillPaint.setARGB(255, 0, 255, 0);
fillPaint.setStyle(Paint.Style.FILL);
canvas.drawPaint(fillPaint) ;
*/
Paint strokePaint = paint;
strokePaint.setARGB(255, 255, 0, 0);
strokePaint.setStyle(Paint.Style.STROKE);
strokePaint.setStrokeWidth(2);
Rect r = canvas.getClipBounds() ;
Rect outline = new Rect( 1,1,r.right-1, r.bottom-1) ;
canvas.drawRect(outline, strokePaint) ;
}
}
<?xml version="1.0" encoding="utf-8"?>
<com.pkg_name.LinearLayoutOutlined
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width=...
android:layout_height=...
>
... your widgets here ...
</com.pkg_name.LinearLayoutOutlined>
Source: Stackoverflow.com