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Android - Custom View and ImageView on XML but Custom View not visible

I try to use setContentView (R.layout.main) to display both an imageview and a Custom View. Somehow only the imageview can be shown but the Custom view is not visible (i.e. Bitmap ButtonStart not visible). I tested my code for onDraw and Texture class (responsible to load a bitmap object) somewhere else and it works fine. So I dunno what goes wrong...
Code for Custom view
public class TitleView extends View {
private Bitmap ButtonStart;
public TitleView (Context context, AttributeSet attrs) {
super (context, attrs);
Texture t2 = new Texture(context);
t2.loadFromAsset("button_Start.png");
ButtonStart = t2.getBitmap();
}
#Override
protected void onDraw (Canvas canvas) {
canvas.drawBitmap (ButtonStart, 0, 0, null);
}
}
MainActivity
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature (Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(R.layout.main_screen_image);
}
}
main_screen_image.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/mainScreenLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
>
<ImageView
android:id="#+id/mainScreenImage"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:scaleType="centerCrop"
android:src="#drawable/screenimage"
>
</ImageView>
<com.lowbband.chimera.TitleView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:id="#+id/titleview"/>
</LinearLayout>
With the code above, only screenimage was shown...

<ImageView
android:id="#+id/mainScreenImage"
android:layout_width="fill_parent"
android:layout_height="fill_parent" //it should be wrap_content otherwise it will take whole space
android:scaleType="centerCrop"
android:src="#drawable/screenimage"
>
</ImageView>
<com.lowbband.chimera.TitleView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:id="#+id/titleview"/>
And if the image is large and still fills the screen then put ScrollView outside LinearLayout

Android ImageView drawing objects

I have this Android program in which I want to display a Rectangle within the ImageView of the parent layout. The components are set on this hierarchy and following the layout listed below. The code to display the rectangle are also indicated below:
LinearLayout [Vertical]
Spinner
ImageView
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<Spinner
android:id="#+id/spinMap"
android:layout_width="match_parent"
android:layout_height="wrap_content"
tools:listitem="#android:layout/simple_spinner_item" />
<ImageView
android:id="#+id/imageMap"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#android:color/black" />
</LinearLayout>
CODE:
public class MainActivty extends Activity {
private Display display;
private Spinner spinMap;
private ImageView imageMap;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initailize();
}
private void initailize() {
display = getWindowManager().getDefaultDisplay();
spinMap = (Spinner) findViewById(R.id.spinMap);
imageMap = (ImageView) findViewById(R.id.imageMap);
imageMap.draw(drawMap());
}
private Canvas drawMap() {
Canvas canvas = new Canvas(Bitmap.createBitmap(display.getWidth(), display.getHeight(), Bitmap.Config.RGB_565));
Paint paint = new Paint();
paint.setColor(Color.RED);
canvas.drawRect(10.0f, 10.0f, 100.0f, 100.0f, paint);
return canvas;
}
}
The problem is that when I run the application, the Rectangle don't get display. How can I display the Rectangle?

I think this can help you Android - Canvas drawLine inside ImageView
You should create bitmap with a rectangle and then feed it to ImageView

android: how to implement canvas draws into a exist view in XML

I have a XML file in my program like:
<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>
Also, I have a canvas draw function in my activity.
public class ImgTestActivity extends Activity {
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
private class iniView extends View {
public iniView(Context context) {
super(context);
// TODO Auto-generated constructor stub
}
#Override
protected void onDraw(Canvas canvas) {
// TODO Auto-generated method stub
super.onDraw(canvas);
//set background color
canvas.drawColor(Color.WHITE);
Paint paint = new Paint();
paint.setAntiAlias(true);
paint.setColor(Color.RED);
paint.setStyle(Paint.Style.STROKE);
paint.setStrokeWidth(3);
canvas.drawCircle(this.getWidth()/2, this.getHeight()/2, 30, paint);
}
}
}
I read some articles from Internet. Some people create there own view in activity and set the paint into it.
public　void　onCreate(Bundle　savedInstanceState)　{
　　　　　　　　super.onCreate(savedInstanceState);
　　　　　　　　MyView　myView=new　MyView(this);
　　　　　　　　setContentView(myView);
　　　　}
But I want to set my paint into this two LinearLayout.
<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"/>
How can I do that? (I want to draw two same circles in the center of this two linear layout)

One solution would be to extract the initView (should be CamelCase btw) and then inject it into the xml with the full path name of the class of the View as the tag name. Let's see an example. The resultant class should look like this:
package your.package;
// imports
private class CircleView extends View {
public iniView(Context context) {
super(context);
}
#Override
protected void onDraw(Canvas canvas) {
// your painting stuff
}
}
And the the xml should be something like this:
<your.package.CircleView
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1"
android:background="#ef3"
android:id="#+id/img01"/>
<your.package.CircleView
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1"
android:background="#E8A2B4"
android:id="#+id/img02"/>
Although you may want to have a look at the available Drawable resources in Android: http://developer.android.com/guide/topics/resources/drawable-resource.html
There is a Shape Drawable type that may allow you to do what you want in a simpler way and separated from the business logic of the Activity.
Hope it helps

You can render your xml view using this:
View viewalias = (View) this.findViewById(R.layout.yourxml);, then draw on it as you like, for more details, see this.

try this :
...
import android.util.AttributeSet;
...
public iniView(Context context, AttributeSet attributeSet) {
super(context, attributeSet);
}
...

How to scroll bitmaps?

I have one image view (assigned one bitmap to it) and another bitmap (Transparent) for painting. How it is possible to scroll this bitmap and background bitmap at the same time to be painted at different places.

From what I understood you are trying to draw on top of a image. If thats the case, create a custom view and get the image using BitmapFactory. After you get a bitmap object, use its copy method and use that copy for the canvas of the view.
Now you can override the onDraw method of a custom view and draw anything on top of it.
This view can be added to the layout, and scrolling will happen to the view.
Edit: Sample Code
Ok this is some code that might help you. I dont have the time to go through all your code.
But I tried to understand your requirement.
I am showing the code for an activity, its xml and custom view
Activity.java
public class DrawDemo extends Activity {
private FrameLayout container;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.draw_demo_layout);
container = (FrameLayout)findViewById(R.id.sc);
container.addView(new DrawView(this));
}
public void drawHandler(View target){
container.addView(new DrawView(this));
}
public void clearHandler(View target){
if(container.getChildCount() != 1){
container.removeViewAt(container.getChildCount()-1);
}
}
}
draw_demo_layout.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent" android:layout_height="fill_parent"
android:orientation="vertical">
<FrameLayout android:orientation="vertical"
android:layout_width="fill_parent" android:layout_height="0dip"
android:id="#+id/sc" android:scrollbars="horizontal"
android:layout_weight="1.0">
<ImageView android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:src="#drawable/chips"/>
</FrameLayout>
<Button android:layout_width="fill_parent"
android:layout_height="wrap_content" android:text="Draw"
android:onClick="drawHandler"/>
<Button android:layout_width="fill_parent"
android:layout_height="wrap_content" android:text="Clear"
android:onClick="clearHandler"/>
</LinearLayout>
DrawView.java
public class DrawView extends View {
public DrawView(Context context) {
super(context);
setLayoutParams(new LayoutParams(LinearLayout.LayoutParams.FILL_PARENT
,LinearLayout.LayoutParams.FILL_PARENT));
}
public DrawView(Context context, AttributeSet attrs) {
super(context, attrs);
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
Paint p = new Paint();
p.setColor(Color.RED);
p.setStrokeWidth(5);
canvas.drawLine(50, 50, 100, 150, p);
canvas.drawLine(100, 150, 20, 50, p);
}
}
This activity has a framelayout which has a imageview as the base which holds the bitmap.
We add a custom draw view on top of it and do our drawings on it.When we want to clear the drawing we remove the drawview and add another one if we need to draw again.
This might not be the most efficient way. But should get you started.

main.xml hiding the view help

I am unable to display both the setContentView(R.layout.main) and View together. I think I am not getting the concept right. Could anyone explain me where I am going wrong. Thank you. //please read the comment in code
I am trying to display a image on main.xml using BitmapFactory.
public class TryGraph extends Activity
{
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);//I think this is where I need your help
setContentView(new myView(this));//I want this to be displayed in main.xml
}
private class myView extends View{
public myView(Context context) {
super(context);
// TODO Auto-generated constructor stub
}
#Override
protected void onDraw(Canvas canvas) {
// TODO Auto-generated method stub
Bitmap myBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.sinewave);
Bitmap resizedBitmap = Bitmap.createBitmap(myBitmap, 0, 0,
300, 143);
canvas.drawBitmap(resizedBitmap, 60, 50, null);
Paint myPaint = new Paint();
myPaint.setColor(Color.RED);
myPaint.setStyle(Paint.Style.STROKE);
myPaint.setStrokeWidth(5);
canvas.drawRect(250,255,260,250, myPaint);
}
}
}
THE XML FILE IS

When you call setContentView you are telling the device to load the entire layout that should be displayed to the user. In most cases this view will occupy the entire screen. Now this Layout file is considered the root and may contain child views, one of which should be your ImageView.
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<TextView
android:id="#+id/banner"
android:text="hello world"
>
<ImageView
android:id="#+id/myImageView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="#drawable/sampleimage"
/>
<?LinearLayout>
This ImageView can now be accessed by code through the use of findViewById(R.id.myImageView) and you can then use the BitmapFactory to set your image. If the image is not going to be changed, you can just set it in the layout file android:src="#drawable/sampleimage"