Develop Reference

adding button onto a view programatically

If I want to add a button in this class so that I can call the onclicklistener, how should I do it?i have also provided the activity class onto which i am adding this view.
activity:
import android.app.Activity;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewGroup.LayoutParams;
import android.widget.Button;
import android.widget.RelativeLayout;
import android.content.Context;
public class NewGame extends Activity {
View view;
Context context;
RelativeLayout layout;
GameView gameview;
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
gameview=new GameView(this);
setContentView(gameview);
//layout = (RelativeLayout) findViewById(R.id.relative_layout);
//layout.addView(gameview);
}
}
view:
public class GameView extends View {
Path circle;
Paint cPaint;
Paint tPaint;
String z;
int i = 65, strt, arc, leftx, topy, rightx, bottomy, maxx, maxy;
boolean flag1, flag2, flag3;
double n1, n2;
int n, n3 = 180,n4,n5 = 90;
float f1 = 180, f2 = 90;
Button b1;
Random r = new Random();
RectF oval;
public GameView(Context context) {
super(context);
leftx = 0;
topy = 60;
rightx = 150;
bottomy = 120;
z = String.valueOf(Character.toChars(i));
cPaint = new Paint();
cPaint.setColor(Color.RED);
strt = 45;
arc = 315;
n1 = Math.random() * 600;
Log.d("random", z);
if (flag2 == false)
new DrawThread(this);
// cPaint.setStrokeWidth(2);
tPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
tPaint.setStyle(Paint.Style.FILL_AND_STROKE);
tPaint.setColor(Color.BLACK);
float scale = getResources().getDisplayMetrics().scaledDensity;
tPaint.setTextSize(20 * scale);
}
public void onSizeChanged(int w,int h,int oldh,int oldw) {
maxx = oldw;
maxy = oldh;
}
//#Override
protected void onDraw(Canvas canvas) {
// Drawing commands go here
oval = new RectF(leftx,topy,rightx,bottomy);
canvas.drawArc(oval, strt, arc, true, cPaint);
while (i < 90) {
canvas.drawText(String.valueOf(Character.toChars(i)),f1,f2, tPaint);
break;
}
}
}

You can do it like this:
Button bt = new Button(this);
bt.setText("A Button");
bt.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT));
linerLayout.addView(bt);
And then you can do this
bt.setOnClickListener(new View.OnClickListener() {
//TO DO
}
I hope that this can help you.

first of all in order to allow to your custom view to have an addView(View v) method it must extend ViewGroup instead of View; then you can use this code
b1=new Button(context);
b1.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT ));
b1.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
}
});
this.addView(b1);

GridView on my GameView (SurfaceView)

I have the following problem.
I am trying to code a Tetris Game for Android. Therefore I need to put a Grid on the GameView (a self coded class, which extends the SurfaceVieW).
Unfortunately I do not know how to draw the Grid on the GameView.
I already implemented a Grid class, which sets the width and height of the rows and columns.
My Grid Class
package com.example.tetris;
import android.content.Context;
import android.graphics.Paint;
import android.widget.GridView;
public class Grid extends GridView
{
private int rowsWidth;
private int columnsHeight;
private int rowsNum;
private int columnsNum;
private Paint gridcolor;
private GameView gameview;
public Grid(Context context)
{
super(context);
}
public void drawGrid(GameView gameview)
{
this.gameview = gameview;
rowsWidth = gameview.getWidth() / 10;
rowsNum = gameview.getWidth() / rowsWidth;
columnsHeight = gameview.getHeight()/rowsWidth;
columnsNum = gameview.getHeight() / columnsHeight;
setHorizontalSpacing(1);
setColumnWidth(rowsWidth);
setNumColumns(columnsNum);
}
}
My GameView Class
package com.example.tetris;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.view.MotionEvent;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.widget.GridView;
public class GameView extends SurfaceView {
private SurfaceHolder surfaceHolder;
private Tetriminos[] tetriminos[];
private GridView grid;
public GameView(Context context)
{
super(context);
final GameLoopThread gameloop = new GameLoopThread(this); // warum er final erzwingt, ka
surfaceHolder = getHolder();
surfaceHolder.addCallback(new SurfaceHolder.Callback()
{
#Override
public void surfaceChanged(SurfaceHolder holder, int format,
int width, int height) {
// TODO Auto-generated method stub
}
#Override
public void surfaceCreated(SurfaceHolder holder) {
gameloop.setRunning(true);
gameloop.start();
}
#Override
public void surfaceDestroyed(SurfaceHolder holder) {
gameloop.setRunning(false);
}
});
}
protected void onDraw(Canvas canvas) {
canvas.drawColor(Color.BLACK);
drawBorders(canvas);
// grid.drawGrid(this);
}
public boolean onTouchEvent(MotionEvent event) {
return false;
}
public void drawBorders(Canvas canvas)
{
int borderwidth = 10;
int screenWidth = getWidth();
int screenHeight = getHeight();
Paint bordercolor = new Paint();
bordercolor.setARGB(255, 236, 27, 36);
canvas.drawRect(0, 0, borderwidth, getHeight(), bordercolor);
canvas.drawRect(0, getHeight()-borderwidth, getWidth(), getHeight(), bordercolor);
canvas.drawRect(getWidth()-borderwidth, 0, getWidth(), getHeight(), bordercolor);
canvas.drawRect(0, 0, getWidth(), borderwidth, bordercolor);
}
}

onDraw not firing when created

My custom view's onDraw() is not being fired. Why? I am using 2.3.3. Shouldn't the view automatically draw when it gets created? The onMeasure() method is being fired and I get the correct screen width and height.
package com.example.assignment2b;
import android.os.Bundle;
import android.app.Activity;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.util.Log;
import android.view.Display;
import android.view.Menu;
import android.view.View;
import android.view.WindowManager;
public class AcesActivity extends Activity {
private static final String TAG = "DEBUG";
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
HeartView heartView = new HeartView(this);
setContentView(heartView);
heartView.invalidate();
}
class HeartView extends View {
private int screenWidth;
private int screenHeight;
private Context context;
public HeartView(Context context) {
super(context);
this.context = context;
}
#Override
public void onDraw(Canvas canvas) {
Log.println(Log.DEBUG, TAG, "onDraw fired");
int cardWidth = screenWidth - 10;
int cardHeight = (int) (cardWidth * 1.4);
canvas.drawColor(Color.DKGRAY);
Paint paint = new Paint();
paint.setColor(Color.WHITE);
paint.setStyle(Paint.Style.FILL);
canvas.drawRect(5, (screenHeight/2) - (cardHeight/2), screenWidth - 5, (screenHeight/2) + (cardHeight/2), paint);
paint.setColor(Color.BLACK);
paint.setStyle(Paint.Style.STROKE);
canvas.drawRect(5, (screenHeight/2) - (cardHeight/2), screenWidth - 5, (screenHeight/2) + (cardHeight/2), paint);
}
#Override
public void onMeasure(int width, int height) {
Log.println(Log.DEBUG, TAG, "onMeasure fired");
WindowManager wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
Display display = wm.getDefaultDisplay();
screenWidth = display.getWidth();
screenHeight = display.getHeight();
setMeasuredDimension(screenWidth, screenHeight);
Log.println(Log.DEBUG, TAG, "screenWidth = " + screenWidth);
Log.println(Log.DEBUG, TAG, "scrrenHeight = " + screenHeight);
super.onMeasure(screenWidth, screenHeight);
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
return true;
}
}

A few different issues going on. First as #dragonwrenn suggested, without a ViewGroup and layout params, your view has no intrinsic bounds. The call to invalidate() is unnecessary, but not problematic.
public class AcesActivity extends Activity {
private static final String TAG = "DEBUG";
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
RelativeLayout rl = new RelativeLayout(this);
RelativeLayout.LayoutParams params = new
RelativeLayout.LayoutParams(LayoutParams.MATCH_PARENT,
LayoutParams.MATCH_PARENT);
setContentView(rl);
HeartView heartView = new HeartView(this);
heartView.setLayoutParams(params);
rl.addView(heartView);
}
class HeartView extends View {
private int screenWidth;
private int screenHeight;
private Context context;
// Moved a couple of variable declarations out of the onDraw method
Paint paint;
int cardWidth;
int cardHeight;
public HeartView(Context context) {
super(context);
this.context = context;
paint = new Paint();
}
Second, your math for the rects drew them beyond the borders of the screen. I put in some hard numbers just as a test. You will want to rework your numbers to get what you really want. Also, your stroke had no width, so note
#Override
public void onDraw(Canvas canvas) {
Log.println(Log.DEBUG, TAG, "onDraw fired");
canvas.drawColor(Color.DKGRAY);
paint.setColor(Color.WHITE);
paint.setStyle(Paint.Style.FILL);
canvas.drawRect(10, 10, 50, 50, paint);
paint.setColor(Color.BLACK);
paint.setStyle(Paint.Style.STROKE);
paint.setStrokeWidth(3);
canvas.drawRect(10, 10, 50, 50, paint);
}
Third, I'm not sure what everything in onMeasure was trying to achieve, but it was causing issues for the view. You shouldn't need more than what's below:
#Override
public void onMeasure(int width, int height) {
Log.println(Log.DEBUG, TAG, "onMeasure fired");
screenWidth = width;
screenHeight = height;
Log.println(Log.DEBUG, TAG, "screenWidth = " + screenWidth);
Log.println(Log.DEBUG, TAG, "scrrenHeight = " + screenHeight);
super.onMeasure(screenWidth, screenHeight);
cardWidth = screenWidth - 10;
cardHeight = (int) (cardWidth * 1.4);
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
return true;
}
}
Edit: note to original poster, the above is functional code tested in Eclipse. If each section is copied and pasted exactly, it will work.

Do the below changes in your onMeasure() method:
Declare the display metrics in your class.
private DisplayMetrics m_metrics;
#Override
public void onMeasure(int width, int height) {
Log.println(Log.DEBUG, TAG, "onMeasure fired");
Display m_display = getWindowManager().getDefaultDisplay();
m_metrics = context.getResources().getDisplayMetrics();
m_display.getMetrics(m_metrics);
screenWidth = m_display.getWidth();
screenHeight = m_display.getHeight();
super.onMeasure(screenWidth, screenHeight);
}

Android Progressbar with circle radius changes Dynamically

I want to change the circle radius dependent on the slider position
I created both individually.
while apply the circle method to the the Progress bar.
facing error.
Actually I call the Progress-Bar(Seek Bar) with
setContentView(R.layout.main);
and for drawing circle as you know I have to used setContentView(demoview);
Query: I want to merge both layout as display into image.
I didn't have idea will it possible or not?
Any guidance,tutorial appreciable.
Thanks for give your valuable time for my query.
Hope you have solution.

Check this out..
I am not using android seekbar, instead i am drawing a similar seekbar on canvas..
Check if this code can help u..
package com.test;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
public class SampleComp extends View implements OnTouchListener {
private Paint paint = null;
private int width = 0;
private int height = 0;
private int barStartX = 20;
private int barStartY = 20;
private int barEndX;
private int barEndY = 30;
private int radius;
private int heightAvailableForCircle;
private int widthAvailableForCircle;
private int maxRadius;
private int totalSeekBarLength;
private int currentSeekBarLength = 10;
private int whatPercentOfSeekBarIsSelected = 50;
public SampleComp(Context context) {
super(context);
paint = new Paint();
paint.setAntiAlias(true);
setOnTouchListener(this);
}
public SampleComp(Context context, AttributeSet attrs) {
super(context, attrs);
paint = new Paint();
paint.setAntiAlias(true);
}
public SampleComp(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
paint = new Paint();
paint.setAntiAlias(true);
}
#Override
public void onDraw(Canvas canvas){
barEndX = getWidth() - 20;
paint.setColor(Color.WHITE);
setWidth(canvas.getWidth());
setHeight(canvas.getHeight());
setHeightAvailableForCircle(getViewHeight() - barEndY);
setWidthAvailableForCircle(getViewWidth() - 40);
System.out.println("heightAvailableForCircle: "+getAvailableHeightForCircle());
System.out.println("widthAvailableForCircle: "+getWidthAvailableForCircle());
totalSeekBarLength = barEndX - barStartX;
System.out.println("SEEK LEN: "+totalSeekBarLength);
canvas.drawRect(barStartX, barStartY, barEndX, barEndY, paint);
paint.setColor(Color.BLUE);
setMaxRadius(heightAvailableForCircle, widthAvailableForCircle);
whatPercentOfSeekBarIsSelected = getSelectedSeekBarPercentage(totalSeekBarLength,getCurrentSeekBarLenghtSelected());
System.out.println("whatPercentOfSeekBarIsSelected: "+whatPercentOfSeekBarIsSelected);
System.out.println("!!!!!: "+canvas.getWidth());
System.out.println("####: "+getViewWidth());
System.out.println("^^^^^^^^^************: "+ (whatPercentOfSeekBarIsSelected * (getViewWidth() - 40)) / 100);
canvas.drawRect(barStartX, barStartY, ( (whatPercentOfSeekBarIsSelected * (getViewWidth() - 40)) / 100) + 20,
barEndY, paint);
paint.setColor(Color.GRAY);
setRadius(whatPercentOfSeekBarIsSelected);
canvas.drawCircle( (canvas.getWidth())/2, (canvas.getHeight() - 30)/2, radius, paint);
}
private void setRadius(int per){
this.radius = (getMaxRadius() * per)/100;
}
private int getSelectedSeekBarPercentage(int total, int current){
int per = 0;
per = ( (current * 100) / total);
return per;
}
private void setRadius(int total, int current){
System.out.println("total: "+total);
System.out.println("current: "+current);
this.radius = ( ( (getMaxRadius()/2) * current) / 100);
System.out.println("radius: "+this.radius);
}
private void setMaxRadius(int h, int w){
this.maxRadius = h < w ? h/2 : w/2 ;
}
private int getMaxRadius(){
return this.maxRadius;
}
private void setWidth(int w){
this.width = w;
}
private void setHeight(int h){
this.height = h;
}
private int getViewWidth(){
return this.width;
}
private int getViewHeight() {
return this.height;
}
private void setHeightAvailableForCircle(int availableHeightForCircle){
this.heightAvailableForCircle = availableHeightForCircle;
}
private int getAvailableHeightForCircle(){
return this.heightAvailableForCircle;
}
private void setWidthAvailableForCircle(int wid){
this.widthAvailableForCircle = wid;
}
private int getWidthAvailableForCircle(){
return this.widthAvailableForCircle;
}
private void setCurrentSeekBarLength(int x){
this.currentSeekBarLength = x;
}
private int getCurrentSeekBarLenghtSelected(){
return this.currentSeekBarLength;
}
#Override
public boolean onTouch(View v, MotionEvent event) {
int x = (int) event.getX();
int y = (int) event.getY();
System.out.println("x: "+x);
System.out.println("y: "+y);
if(x >= 10 && x<= barEndX && y >= 10 && y <= 30){
System.out.println("TRUE");
setCurrentSeekBarLength(x - 20);
invalidate();
}
return false;
}
}
And this is my Activity class:
package com.test;
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.drawable.BitmapDrawable;
import android.os.Bundle;
import android.widget.ImageView;
public class SampleActivity extends Activity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(new SampleComp(this));
}
}

Can u be little more specific regarding what u want to achieve. Ur question isn't that clear. What i can make out is, u want to increase/decrease the radius of the circle based on the progress bar value.

Have a look at the android custom component guide. You basically have to derive your circle component from android.view.View. Then you can add it to your layout like every other component.

Only one view is displayed in Android

I am new to Android. When i run this code, only one circle is displayed. If i remove view1, then view2 is displayed. but they are never displayed together!!! why is that?
Any help would be appreciated.
thanks
package com.dots;
import android.app.Activity;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.os.Bundle;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.LinearLayout;
import android.widget.TextView;
import android.widget.Toast;
public class Dots1Activity extends Activity
{
private static final String TAG = "DotsActivity";
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
LinearLayout ll = new LinearLayout(this);
ll.setOrientation(LinearLayout.HORIZONTAL);
TextView label = new TextView(this);
LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT);
label.setText("Click the circle!");
CustomDrawableView view1 = new CustomDrawableView(this, 100, 100, 50, Color.RED);
CustomDrawableView view2 = new CustomDrawableView(this, 200, 200, 25, Color.GREEN);
CustomDrawableView view3 = new CustomDrawableView(this, 300, 300, 10, Color.WHITE);
ll.addView(label, layoutParams);
ll.addView(view1, layoutParams);
ll.addView(view2, layoutParams);
ll.addView(view3, layoutParams);
setContentView(ll);
}
}
class CustomDrawableView extends View implements OnClickListener{
private Context context;
private int x, y, radius, color;
public CustomDrawableView(Context context, int x, int y, int radius, int color) {
super(context);
this.context = context;
this.x = x;
this.y =y;
this.radius = radius;
this.color = color;
setOnClickListener(this);
}
protected void onDraw(Canvas canvas)
{
super.onDraw(canvas);
this.setBackgroundColor(Color.LTGRAY);
Paint paint = new Paint (Paint.ANTI_ALIAS_FLAG);
paint.setColor(color);
canvas.drawCircle(x, y, radius, paint);
}
public void onClick(View v) {
Toast.makeText(this.context,
x+"-"+y+"-"+radius,
Toast.LENGTH_SHORT).show();
}
}

ll.setOrientation(LinearLayout.HORIZONTAL);
They are put next to each other. You can't see them, because your display isn't width naught. Put them in a HorizontalScrollView or make them aper VERTICAL.
I'm not sure if this takes effect here, but i found this on the Android Documentation:
Note that the framework will not draw
views that are not in the invalid
region. To force a view to draw, call
invalidate().
Try if this solves your problem (for the moment I guess).
About your Code
Something i noticed: The implemented interface for the onClickListener is View.OnClickListener:
class CustomDrawableView extends View implements View.OnClickListener{ [...] }
How to solve the Problem
I looked around on the Android Docs and found this. They mantioned the method onMeasure(), which:
Measure the view and its content to
determine the measured width and the
measured height.
So I added it to your custom CustomDrawableView-class. Unfortuandly, you can't pass the super.onMeasure()-method simple integers, you'll need to decode them first, using the View.MeasureSpec-class:
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec){
super.onMeasure(View.MeasureSpec.makeMeasureSpec(100, View.MeasureSpec.EXACTLY),
View.MeasureSpec.makeMeasureSpec(100, View.MeasureSpec.EXACTLY));
}
In the Example, I set both width and height to 100px. Also, I did some other improvements on your code:
Dots1Activity-class
import android.app.Activity;
import android.graphics.Color;
import android.os.Bundle;
import android.widget.LinearLayout;
import android.widget.TextView;
public class Dots1Activity extends Activity
{
private static final String TAG = "DotsActivity";
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
LinearLayout ll = new LinearLayout(this);
ll.setOrientation(LinearLayout.VERTICAL);
TextView label = new TextView(this);
LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT);
label.setText("Click the circle!");
CustomDrawableView view1 = new CustomDrawableView(this, 50, 50, 50, Color.RED);
CustomDrawableView view2 = new CustomDrawableView(this, 75, 75, 25, Color.GREEN);
CustomDrawableView view3 = new CustomDrawableView(this, 85, 85, 10, Color.WHITE);
ll.addView(label, layoutParams);
ll.addView(view1, layoutParams);
ll.addView(view2, layoutParams);
ll.addView(view3, layoutParams);
setContentView(ll);
}
}
CustomDrawableView-class
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.view.View;
import android.widget.Toast;
class CustomDrawableView extends View implements View.OnClickListener{
private Context context;
private int x, y, radius, color;
public CustomDrawableView(Context context, int x, int y, int radius, int color) {
super(context);
this.context = context;
this.x = x;
this.y =y;
this.radius = radius;
this.color = color;
setOnClickListener(this);
}
protected void onDraw(Canvas canvas)
{
super.onDraw(canvas);
Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
paint.setColor(color);
canvas.drawCircle(x, y, radius, paint);
}
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec){
super.onMeasure(View.MeasureSpec.makeMeasureSpec(100, View.MeasureSpec.EXACTLY),
View.MeasureSpec.makeMeasureSpec(100, View.MeasureSpec.EXACTLY));
}
public void onClick(View v) {
Toast.makeText(this.context,
x+"-"+y+"-"+radius,
Toast.LENGTH_SHORT).show();
}
}
This code compiles, shows all the circles and the onClick-Event works, too.
Although I have to say it was a bit of a challenge and I'm grateful for it.

change the orientation of you layout to vertical like this :
ll.setOrientation(LinearLayout.VERTICAL);