Develop Reference

changing image with imageswitcher and onTouch

I want to make android app like the following site.
https://sectional-anatomy.org/ct-abdomen/ or like https://radiopaedia.org/cases/squamous-cell-carcinoma-oral-cavity
There are multiple pictures and these are changing by scrolling.
I have done something like that with imageswitcher and onTouch event with action_down and action_up but it doesn't work because when I remove my finger then it goes to the first image it doesn't stay where I left.
Here is my code:
package com.radiology.radiologymenu.tomografi;
import android.content.SharedPreferences;
import android.graphics.Point;
import android.os.Bundle;
import android.os.Handler;
import android.preference.PreferenceManager;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.view.Display;
import android.view.KeyEvent;
import android.view.MotionEvent;
import android.view.View;
import android.view.WindowManager;
import android.webkit.WebView;
import android.widget.Button;
import android.widget.FrameLayout;
import android.widget.HorizontalScrollView;
import android.widget.ImageSwitcher;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;
import android.widget.Toast;
import android.widget.ViewSwitcher;
import com.radiology.radiologymenu.R;
import java.util.ArrayList;
import java.util.Timer;
import java.util.TimerTask;
public class ImageChangeActivity extends AppCompatActivity {
private ImageSwitcher imageSwitcher;
private ImageView box;
// Size
private int frameHeight;
private int boxSize;
private int screenHeight;
// Position
private int boxY;
// Speed
private int boxSpeed;
// Score
private int score = 0;
// Initialize Class
private Handler handler = new Handler();
private Timer timer = new Timer();
// Status Check
private boolean action_flg = false;
private boolean start_flg = false;
private String pic;
private ArrayList<Integer> slidePictures;
private static final Integer[] image= {
R.drawable.sagittal_boyun_1, R.drawable.sagittal_boyun_2, R.drawable.sagittal_boyun_3, R.drawable.sagittal_boyun_4,
R.drawable.sagittal_boyun_5, R.drawable.sagittal_boyun_6, R.drawable.sagittal_boyun_7, R.drawable.sagittal_boyun_8,
R.drawable.sagittal_boyun_9, R.drawable.sagittal_boyun_10, R.drawable.sagittal_boyun_11,
R.drawable.sagittal_boyun_12, R.drawable.sagittal_boyun_13, R.drawable.sagittal_boyun_14, R.drawable.sagittal_boyun_15,
R.drawable.sagittal_boyun_16, R.drawable.sagittal_boyun_17, R.drawable.sagittal_boyun_18, R.drawable.sagittal_boyun_19,
R.drawable.sagittal_boyun_20, R.drawable.sagittal_boyun_21, R.drawable.sagittal_boyun_22, R.drawable.sagittal_boyun_23,
R.drawable.sagittal_boyun_24, R.drawable.sagittal_boyun_25, R.drawable.sagittal_boyun_26, R.drawable.sagittal_boyun_27,
R.drawable.sagittal_boyun_28, R.drawable.sagittal_boyun_29, R.drawable.sagittal_boyun_30, R.drawable.sagittal_boyun_31,
R.drawable.sagittal_boyun_32, R.drawable.sagittal_boyun_33, R.drawable.sagittal_boyun_34, R.drawable.sagittal_boyun_35,
R.drawable.sagittal_boyun_36, R.drawable.sagittal_boyun_37, R.drawable.sagittal_boyun_38, R.drawable.sagittal_boyun_39,
R.drawable.sagittal_boyun_40, R.drawable.sagittal_boyun_41, R.drawable.sagittal_boyun_42, R.drawable.sagittal_boyun_43,
R.drawable.sagittal_boyun_44, R.drawable.sagittal_boyun_45 };
int i = 0;
#Override
protected void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.slide_activity_main);
pic = getIntent().getExtras().getString("pic");
slidePictures = (ArrayList<Integer>) getIntent().getExtras().getSerializable("slidePictures");
getView2(pic,slidePictures);
}
public void getView2(String strings, ArrayList<Integer> slidePictures){
setContentView(R.layout.slide_activity_main);
TextView textView = (TextView) findViewById(R.id.resimText);
textView.setText(strings.toString());
imageSwitcher = (ImageSwitcher) findViewById(R.id.imageSwitcher);
box = (ImageView) findViewById(R.id.box);
// Get screen size.
WindowManager wm = getWindowManager();
Display disp = wm.getDefaultDisplay();
Point size = new Point();
disp.getSize(size);
screenHeight = size.y;
boxSpeed = Math.round(screenHeight / 60); // 1280 / 60 = 21.333... => 21
imageSwitcher.setFactory(new ViewSwitcher.ViewFactory() {
#Override
public View makeView() {
ImageView imageView = new ImageView(getApplicationContext());
imageView.setScaleType(ImageView.ScaleType.FIT_XY);
FrameLayout.LayoutParams params = new ImageSwitcher.LayoutParams(
FrameLayout.LayoutParams.MATCH_PARENT, FrameLayout.LayoutParams.MATCH_PARENT);
imageView.setLayoutParams(params);
return imageView;
}
});
imageSwitcher.setImageResource(slidePictures.get(0));
}
#Override
public boolean onKeyDown(int keyCode, KeyEvent event)
{
if ((keyCode == KeyEvent.KEYCODE_BACK))
{
finish();
}
return super.onKeyDown(keyCode, event);
}
public void changePos() {
// Move Box
if (action_flg == true) {
// Touching
boxY -= boxSpeed;
if (i<slidePictures.size()-1){
i++;
imageSwitcher.setImageResource(slidePictures.get(i));
}
} else {
// Releasing
boxY += boxSpeed;
if (i>0){
i--;
imageSwitcher.setImageResource(slidePictures.get(i));
}
}
// Check box position.
if (boxY < 0) boxY = 0;
if (boxY > frameHeight - boxSize) boxY = frameHeight - boxSize;
box.setY(boxY);
}
public boolean onTouchEvent(MotionEvent me) {
if (start_flg == false) {
start_flg = true;
// Why get frame height and box height here?
// Because the UI has not been set on the screen in OnCreate()!!
FrameLayout frame = (FrameLayout) findViewById(R.id.frame);
frameHeight = frame.getHeight();
boxY = (int)box.getY();
// The box is a square.(height and width are the same.)
boxSize = box.getHeight();
timer.schedule(new TimerTask() {
#Override
public void run() {
handler.post(new Runnable() {
#Override
public void run() {
changePos();
}
});
}
}, 0, 40);
} else {
if (me.getAction() == MotionEvent.ACTION_DOWN) {
action_flg = false;
} else if (me.getAction() == MotionEvent.ACTION_UP) {
action_flg = true;
}
}
return true;
}
}

Android: Draw text on ImageView with finger touch

i completed the drawing text on ImageView and i saved the final image in sd card. My problem is, when i am touching the screen to draw the text, my image in the ImageView is disappearing.
Code
import java.io.File;
import java.io.FileOutputStream;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.os.StrictMode;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.Bitmap.CompressFormat;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.View.OnTouchListener;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;
public class DrawTextOnImgActivity extends Activity {
private Button btn_save, btn_resume;
private ImageView iv_canvas;
private Bitmap baseBitmap;
private Canvas canvas;
private Paint paint;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_draw_text_on_img);
// The initialization of a brush, brush width is 5, color is red
paint = new Paint();
paint.setStrokeWidth(5);
paint.setColor(Color.RED);
iv_canvas = (ImageView) findViewById(R.id.imageView1);
btn_save = (Button) findViewById(R.id.btn_save);
btn_resume = (Button) findViewById(R.id.btn_resume);
btn_save.setOnClickListener(click);
btn_resume.setOnClickListener(click);
iv_canvas.setOnTouchListener(touch);
}
private View.OnTouchListener touch = new OnTouchListener() {
// Coordinate definition finger touch
float startX;
float startY;
#SuppressLint("ClickableViewAccessibility")
#Override
public boolean onTouch(View v, MotionEvent event) {
switch (event.getAction()) {
// Press the user action
case MotionEvent.ACTION_DOWN:
// The first drawing initializes the memory image, specify the background is white
if (baseBitmap == null) {
baseBitmap = Bitmap.createBitmap(iv_canvas.getWidth(),
iv_canvas.getHeight(), Bitmap.Config.ARGB_8888);
canvas = new Canvas(baseBitmap);
canvas.drawColor(Color.WHITE);
}
// Recording began to touch point coordinate
startX = event.getX();
startY = event.getY();
break;
// The user's finger on the screen of mobile action
case MotionEvent.ACTION_MOVE:
// Record the coordinates of the mobile point
float stopX = event.getX();
float stopY = event.getY();
//According to the coordinates of the two points, drawing lines
canvas.drawLine(startX, startY, stopX, stopY, paint);
// Update start point
startX = event.getX();
startY = event.getY();
// The pictures to the ImageView
iv_canvas.setImageBitmap(baseBitmap);
break;
case MotionEvent.ACTION_UP:
break;
default:
break;
}
return true;
}
};
private View.OnClickListener click = new OnClickListener() {
#Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.btn_save:
saveBitmap();
break;
case R.id.btn_resume:
resumeCanvas();
break;
default:
break;
}
}
};
/**
* Save the image to the SD card.
*/
protected void saveBitmap() {
try {
// Save the image to the SD card.
File folder = new File(Environment.getExternalStorageDirectory() + "/DrawTextOnImg");
if (!folder.exists()) {
folder.mkdir();
}
File file = new File(Environment.getExternalStorageDirectory()+"/DrawTextOnImg/tempImg.png");
FileOutputStream stream = new FileOutputStream(file);
baseBitmap.compress(CompressFormat.PNG, 100, stream);
Toast.makeText(DrawTextOnImgActivity.this, "Save the picture of success", Toast.LENGTH_SHORT).show();
// Android equipment Gallery application will only at boot time scanning system folder
// The simulation of a media loading broadcast, for the preservation of images can be viewed in Gallery
Intent intent = new Intent();
intent.setAction(Intent.ACTION_MEDIA_MOUNTED);
intent.setData(Uri.fromFile(Environment.getExternalStorageDirectory()));
sendBroadcast(intent);
} catch (Exception e) {
Toast.makeText(DrawTextOnImgActivity.this, "Save failed", Toast.LENGTH_SHORT).show();
e.printStackTrace();
}
}
/**
* Clear the drawing board
*/
protected void resumeCanvas() {
// Manually clear the drawing board, to create a drawing board
if (baseBitmap != null) {
baseBitmap = Bitmap.createBitmap(iv_canvas.getWidth(), iv_canvas.getHeight(), Bitmap.Config.ARGB_8888);
canvas = new Canvas(baseBitmap);
canvas.drawColor(Color.WHITE);
iv_canvas.setImageBitmap(baseBitmap);
Toast.makeText(DrawTextOnImgActivity.this, "Clear the drawing board, can be re started drawing", Toast.LENGTH_SHORT).show();
}
}
}
Manifest
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<protected-broadcast android:name="android.intent.action.MEDIA_MOUNTED" />
By using this code i am writing the text on ImageView but image in the ImageView is disappearing. So, please help me to write the text on image of ImageView

I achieved it by fallowing this code
DrawTextOnImgActivity
import java.io.File;
import java.io.FileOutputStream;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore.Images;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;
import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.Bitmap.CompressFormat;
import android.graphics.Canvas;
public class DrawTextOnImgActivity extends Activity {
ImageView ivDrawImg;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_draw_text_on_img);
ivDrawImg = (ImageView) findViewById(R.id.iv_draw);
Button btnSave = (Button) findViewById(R.id.btn_save);
Button btnResume = (Button) findViewById(R.id.btn_resume);
btnSave.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
saveImg();
}
});
btnResume.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
}
});
}
private void saveImg(){
Bitmap image = Bitmap.createBitmap(ivDrawImg.getWidth(), ivDrawImg.getHeight(), Bitmap.Config.RGB_565);
ivDrawImg.draw(new Canvas(image));
String uri = Images.Media.insertImage(getContentResolver(), image, "title", null);
Log.e("uri", uri);
try {
// Save the image to the SD card.
File folder = new File(Environment.getExternalStorageDirectory() + "/DrawTextOnImg");
if (!folder.exists()) {
folder.mkdir();
//folder.mkdirs(); //For creating multiple directories
}
File file = new File(Environment.getExternalStorageDirectory()+"/DrawTextOnImg/tempImg.png");
FileOutputStream stream = new FileOutputStream(file);
image.compress(CompressFormat.PNG, 100, stream);
Toast.makeText(DrawTextOnImgActivity.this, "Picture saved", Toast.LENGTH_SHORT).show();
// Android equipment Gallery application will only at boot time scanning system folder
// The simulation of a media loading broadcast, for the preservation of images can be viewed in Gallery
/*Intent intent = new Intent();
intent.setAction(Intent.ACTION_MEDIA_MOUNTED);
intent.setData(Uri.fromFile(Environment.getExternalStorageDirectory()));
sendBroadcast(intent);*/
} catch (Exception e) {
Toast.makeText(DrawTextOnImgActivity.this, "Save failed", Toast.LENGTH_SHORT).show();
e.printStackTrace();
}
}
}
DrawView
import java.util.ArrayList;
import java.util.List;
import android.annotation.SuppressLint;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.widget.ImageView;
public class DrawView extends ImageView {
private int color = Color.parseColor("#0000FF");
private float width = 4f;
private List<Holder> holderList = new ArrayList<Holder>();
private class Holder {
Path path;
Paint paint;
Holder(int color, float width) {
path = new Path();
paint = new Paint();
paint.setAntiAlias(true);
paint.setStrokeWidth(width);
paint.setColor(color);
paint.setStyle(Paint.Style.STROKE);
paint.setStrokeJoin(Paint.Join.ROUND);
paint.setStrokeCap(Paint.Cap.ROUND);
}
}
public DrawView(Context context) {
super(context);
init();
}
public DrawView(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
public DrawView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
init();
}
private void init() {
holderList.add(new Holder(color, width));
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
for (Holder holder : holderList) {
canvas.drawPath(holder.path, holder.paint);
}
}
#SuppressLint("ClickableViewAccessibility")
#Override
public boolean onTouchEvent(MotionEvent event) {
float eventX = event.getX();
float eventY = event.getY();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
holderList.add(new Holder(color,width));
holderList.get(holderList.size() - 1).path.moveTo(eventX, eventY);
return true;
case MotionEvent.ACTION_MOVE:
holderList.get(holderList.size() - 1).path.lineTo(eventX, eventY);
break;
case MotionEvent.ACTION_UP:
break;
default:
return false;
}
invalidate();
return true;
}
public void resetPaths() {
for (Holder holder : holderList) {
holder.path.reset();
}
invalidate();
}
public void setBrushColor(int color) {
this.color = color;
}
public void setWidth(float width) {
this.width = width;
}
}
Layout (activity_draw_text_on_img)
<RelativeLayout 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:background="#FFFFFF" >
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="250dp"
android:layout_centerInParent="true"
android:background="#FFFFFF" >
<com.app.drawtextonimg.DrawView
android:id="#+id/iv_draw"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:adjustViewBounds="true"
android:src="#drawable/rajamouli" />
</RelativeLayout>
<Button
android:id="#+id/btn_save"
android:layout_width="match_parent"
android:layout_height="40dp"
android:layout_alignParentBottom="true"
android:background="#000000"
android:text="#string/save"
android:textColor="#FFFFFF" />
<Button
android:id="#+id/btn_resume"
android:layout_width="match_parent"
android:layout_height="40dp"
android:background="#000000"
android:text="#string/resume"
android:textColor="#FFFFFF" />
</RelativeLayout>
Manifest file
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
Project link

If I understand your question correctly, I think that you should remove this line from your Case.ACTION_MOVE.
iv_canvas.setImageBitmap(baseBitmap);
By doing this you are resetting your ImageView every time you move on the screen which will cause the ImageView to be just a blank

AnimationDrawable into framelayout beside SurfaceView- Android

Hello all,
in my app, can i make an character (like, cartoon character...) to animate when i touch the screen?
i have another bitmaps (static not animated) on the screen.
i have all this character (10) bitmaps in all animation position (like a cartoon)
this is the code.. ( I NEED TO ANIMATE IT FOR EACH TOUCH )
`
import java.util.ArrayList;
import java.util.List;
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.drawable.AnimationDrawable;
import android.os.Bundle;
import android.view.MotionEvent;
import android.view.View;
import android.view.Window;
import android.widget.FrameLayout;
import android.widget.FrameLayout.LayoutParams;
import android.widget.ImageView;
public class Show extends Activity
{
private Bitmap imageOne;
private Bitmap imageTwo;
private Bitmap imageThree;
private List<Bitmap> images;
private ExplainView myView;
private AnimationDrawable animation;
private ImageView image;`
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(0x00000400, 0x00000400);
setContentView(R.layout.frame_layout);
image = new ImageView(this);
image.setBackgroundResource(R.drawable.tom_anim);
animation = (AnimationDrawable) rocketImage.getBackground();
images = new ArrayList<Bitmap>();
praper();
myView = new ExplainView(this,images,1); <------ this is the surface view class
FrameLayout fl = (FrameLayout)findViewById(R.id.frameLayout);
fl.addView(myView);
fl.addView(image);
}
#Override
public boolean onTouchEvent(MotionEvent event)
{
if(event.getAction() == MotionEvent.ACTION_DOWN)
{
new Runnable() {
#Override
public void run() {
image.setVisibility(View.VISIBLE);
animation.stop();
animation.start();
}
};
}
return true;
}
private void praper()
{
imageOne = BitmapFactory.decodeResource(getResources(), R.drawable.trans_ar_alpha_1);
imageTwo = BitmapFactory.decodeResource(getResources(), R.drawable.trans_ar_alpha_2);
imageThree = BitmapFactory.decodeResource(getResources(), R.drawable.trans_ar_alpha_3);
images.add(0,imageOne);
images.add(1, imageTwo);
images.add(2, imageThree);
}
#Override
public void onWindowFocusChanged(boolean hasFocus) {
// TODO Auto-generated method stub
if(hasFocus)
{
animation.start();
}
else
{
animation.stop();
}
}
}`

of course you can simply by using
#Override
public boolean onTouch(View arg0, MotionEvent arg1) {
// TODO Auto-generated method stub
x = arg1.getX();
y = arg1.getY();
switch(arg1.getAction())
{
case MotionEvent.ACTION_DOWN:
sx=arg1.getX();
sy = arg1.getY();
break;
case MotionEvent.ACTION_UP:
fx=arg1.getX();
fy = arg1.getY();
break;
}

How to add Color Picker in Application?

I have developed an Application , which uses screen as a Slate and finger as a Chalk, which is working properly. But I want to use different color types for chalk.
Here is my Code:
MyDemo.java
package com.example.mydemo;
import android.os.Bundle;
import android.app.Activity;
import android.view.View;
import android.widget.Button;
import android.widget.LinearLayout;
public class MyDemo extends Activity {
private LinearLayout root;
private Button btnReset;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_my_demo);
root = (LinearLayout) findViewById(R.id.root);
btnReset = (Button) findViewById(R.id.reset);
final MyImageView view = new MyImageView(this);
view.setLayoutParams(new LinearLayout.LayoutParams(LinearLayout.LayoutParams.FILL_PARENT, LinearLayout.LayoutParams.FILL_PARENT));
root.addView(view);
btnReset.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
view.reset();
}
});
}
}
MyImageView.java
package com.example.mydemo;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.PointF;
import android.view.MotionEvent;
import android.view.View;
import android.widget.ImageView;
import java.util.ArrayList;
import java.util.List;
public class MyImageView extends ImageView implements View.OnTouchListener {
private int id = -1;
private Path path;
private List<Path> paths = new ArrayList<Path>();
private List<PointF> points = new ArrayList<PointF>();
boolean multiTouch = false;
public MyImageView(Context context) {
super(context);
this.setOnTouchListener(this);
}
public void reset() {
paths.clear();
points.clear();
path = null;
id = -1;
invalidate();
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
Paint paint = createPen(Color.BLACK);
paint.setStyle(Paint.Style.STROKE);
for (Path path : paths) {
canvas.drawPath(path, paint);
}
for (int i = 0; i < points.size(); i++) {
PointF p = points.get(i);
canvas.drawText("" + p.x, p.y, i, createPen(Color.WHITE));
}
}
private PointF copy(PointF p) {
PointF copy = new PointF();
copy.set(p);
return copy;
}
public boolean onTouch(View v, MotionEvent event) {
int action = event.getAction();
switch (action & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN:
multiTouch = false;
id = event.getPointerId(0);
PointF p = getPoint(event, id);
path = new Path();
path.moveTo(p.x, p.y);
paths.add(path);
points.add(copy(p));
break;
case MotionEvent.ACTION_POINTER_DOWN:
multiTouch = true;
for (int i = 0; i < event.getPointerCount(); i++) {
int tId = event.getPointerId(i);
if (tId != id) {
points.add(getPoint(event,i));
}
}
break;
case MotionEvent.ACTION_MOVE:
if (!multiTouch) {
p =getPoint(event, id);
path.lineTo(p.x, p.y);
}
break;
}
invalidate();
return true;
}
private PointF getPoint(MotionEvent event, int i) {
int index = 0;
return new PointF(event.getX(index), event.getY(index));
}
private Paint createPen(int color) {
Paint pen = new Paint();
pen.setColor(color);
float width = 3;
pen.setStrokeWidth(width);
return pen;
}
}
activity_my_demo.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout android:id="#+id/root" xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<Button android:id="#+id/reset" android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Reset"
/>
</LinearLayout>
Can any one tell me what should be added or changed in my code so that I can use different colors for Chalk?

You can take the sample in your android folder's..
For the color picker go to in this folder:
android/samples/android-YOURS_VERSION/ApiDemos

Use this, review this code. than your problem will be solve
package com.example.changecolor;
import android.app.Activity;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.graphics.Color;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.TextView;
public class MainActivity extends Activity
implements View.OnClickListener, UberColorPickerDialog.OnColorChangedListener {
private int mColor = 0xFFFF0000;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//Write the version number
PackageManager pm = getPackageManager();
String versionName = "";
try {
PackageInfo pi = pm.getPackageInfo("com.keithwiley.android.ubercolorpickerdemo", 0);
versionName = pi.versionName;
}
catch (Exception e) {
}
TextView textView = (TextView) findViewById(R.id.version);
textView.setText(versionName);
//Initialize the sample
((LinearLayout) findViewById(R.id.LinearLayout)).setBackgroundColor(mColor);
float hsv[] = new float[3];
Color.colorToHSV(mColor, hsv);
if (UberColorPickerDialog.isGray(mColor))
hsv[1] = 0;
if (hsv[2] < .5)
((TextView) findViewById(R.id.sample)).setTextColor(Color.WHITE);
else ((TextView) findViewById(R.id.sample)).setTextColor(Color.BLACK);
//Set up the buttons
Button button = (Button) findViewById(R.id.colorPickerWithTitle);
button.setOnClickListener(this);
button = (Button) findViewById(R.id.colorPickerWithToast);
button.setOnClickListener(this);
}
protected void onPause() {
super.onPause();
}
protected void onResume() {
super.onResume();
}
public boolean onCreateOptionsMenu(Menu menu) {
super.onCreateOptionsMenu(menu);
return true;
}
public boolean onPrepareOptionsMenu(Menu menu) {
super.onPrepareOptionsMenu(menu);
return true;
}
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
}
return super.onOptionsItemSelected(item);
}
public void onClick(View v) {
if (v.getId() == R.id.colorPickerWithTitle)
new UberColorPickerDialog(this, this, mColor, true).show();
if (v.getId() == R.id.colorPickerWithToast)
new UberColorPickerDialog(this, this, mColor, false).show();
}
public void colorChanged(int color) {
((LinearLayout) findViewById(R.id.LinearLayout)).setBackgroundColor(mColor=color);
float hsv[] = new float[3];
Color.colorToHSV(mColor, hsv);
//if (UberColorPickerDialog.isGray(mColor))
// hsv[1] = 0;
if (hsv[2] < .5)
((TextView) findViewById(R.id.sample)).setTextColor(Color.WHITE);
else ((TextView) findViewById(R.id.sample)).setTextColor(Color.BLACK);
}
}
And use the color picker class

How to clear canvas in a surface view?

I am developing an Android Digital signature app in which user can sign and i have to save this file as image.i am using SurfaceView for drawing. DigitalSignatureActivity has two Buttons Save,Clear.
1.Save Button to save file as image
2.Clear Button to clear surface.
But i am unable to clear the surface.i tried drawingSurface.setBackgroundColor(Color.BLACK); still previous sign is retained and canvas.drawColor(Color.BLACK); has no effect and
i am able to save file but its not storing signature perfectly(Some contents are missing) please help.
My code is:
DigitalSignatureActivity.java
package com.pop.digitalsign;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.os.Bundle;
import android.os.Environment;
import android.view.MotionEvent;
import android.view.View;
import android.widget.Toast;
public class DigitalSignatureActivity extends Activity implements
View.OnTouchListener {
private DrawingSurface drawingSurface;
private DrawingPath currentDrawingPath;
private Paint currentPaint;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
setCurrentPaint();
drawingSurface = (DrawingSurface) findViewById(R.id.drawingSurface);
drawingSurface.setOnTouchListener(this);
}
private void setCurrentPaint() {
currentPaint = new Paint();
currentPaint.setDither(true);
currentPaint.setColor(Color.WHITE);
currentPaint.setStyle(Paint.Style.STROKE);
currentPaint.setStrokeJoin(Paint.Join.ROUND);
currentPaint.setStrokeCap(Paint.Cap.ROUND);
currentPaint.setStrokeWidth(2);
}
public boolean onTouch(View view, MotionEvent motionEvent) {
if (motionEvent.getAction() == MotionEvent.ACTION_DOWN) {
drawingSurface.setBackgroundColor(0);
currentDrawingPath = new DrawingPath();
currentDrawingPath.paint = currentPaint;
currentDrawingPath.path = new Path();
currentDrawingPath.path.moveTo(motionEvent.getX(),
motionEvent.getY());
currentDrawingPath.path.lineTo(motionEvent.getX(),
motionEvent.getY());
} else if (motionEvent.getAction() == MotionEvent.ACTION_MOVE) {
currentDrawingPath.path.lineTo(motionEvent.getX(),motionEvent.getY());
drawingSurface.addDrawingPath(currentDrawingPath);
} else if (motionEvent.getAction() == MotionEvent.ACTION_UP) {
currentDrawingPath.path.lineTo(motionEvent.getX(),motionEvent.getY());
}
return true;
}
//To save file as Image
public void saveDrawing(View v) throws IOException {
File mediaStorageDir = new File(
Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES),
"MySignatures");
Bitmap nBitmap = drawingSurface.getBitmap();
try {
if (!mediaStorageDir.exists()) {
mediaStorageDir.mkdirs();
}
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss")
.format(new Date());
File mediaFile = new File(mediaStorageDir.getPath()
+ File.separator + "SIGN_" + timeStamp + ".png");
FileOutputStream out = new FileOutputStream(mediaFile);
nBitmap.compress(Bitmap.CompressFormat.PNG, 90, out);
out.flush();
out.close();
Toast.makeText(this, "Signature saved to " + mediaFile,
Toast.LENGTH_LONG).show();
} catch (Exception e) {
e.printStackTrace();
Toast.makeText(getApplicationContext(), "Not saved",
Toast.LENGTH_SHORT).show();
}
}
//To clear Surface
public void clearScreen(View v) {
//drawingSurface.setBackgroundColor(Color.BLACK);
drawingSurface.clear();
}
}
DrawingSurface.java
package com.pop.digitalsign;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.PorterDuff;
import android.util.AttributeSet;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
public class DrawingSurface extends SurfaceView implements SurfaceHolder.Callback {
private Boolean _run;
protected DrawThread thread;
private Bitmap mBitmap;
Canvas canvas;
private CommandManager commandManager;
public DrawingSurface(Context context, AttributeSet attrs) {
super(context, attrs);
getHolder().addCallback(this);
commandManager = new CommandManager();
thread = new DrawThread(getHolder());
}
class DrawThread extends Thread{
public SurfaceHolder mSurfaceHolder;
public DrawThread(SurfaceHolder surfaceHolder){
mSurfaceHolder = surfaceHolder;
}
public DrawThread() {
// TODO Auto-generated constructor stub
}
public void setRunning(boolean run) {
_run = run;
}
#Override
public void run() {
canvas = null;
while (_run){
try{
canvas = mSurfaceHolder.lockCanvas(null);
//canvas.drawColor(Color.WHITE);
if(mBitmap == null){
mBitmap = Bitmap.createBitmap (1, 1, Bitmap.Config.ARGB_8888);;
}
final Canvas c = new Canvas (mBitmap);
c.drawColor(0, PorterDuff.Mode.CLEAR);
commandManager.executeAll(c);
canvas.drawBitmap (mBitmap, 0, 0,null);
} finally {
if(canvas!=null){
mSurfaceHolder.unlockCanvasAndPost(canvas);
}
}
}
}
}
public void addDrawingPath (DrawingPath drawingPath){
commandManager.addCommand(drawingPath);
}
public void clear(){
//Here i want to clear surface
canvas.drawColor(Color.BLACK);//it has no effect
}
public boolean hasMoreUndo(){
return commandManager.hasMoreUndo();
}
public Bitmap getBitmap(){
return mBitmap;
}
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
mBitmap = Bitmap.createBitmap (width, height, Bitmap.Config.ARGB_8888);;
}
public void surfaceCreated(SurfaceHolder holder) {
thread.setRunning(true);
thread.start();
}
public void surfaceDestroyed(SurfaceHolder holder) {
boolean retry = true;
thread.setRunning(false);
while (retry) {
try {
thread.join();
retry = false;
} catch (InterruptedException e) {
}
}
}
}
CommandManager.java
package com.pop.digitalsign;
import android.graphics.Canvas;
import java.util.Iterator;
import java.util.List;
import java.util.Collections;
import java.util.ArrayList;
public class CommandManager {
private List<DrawingPath> currentStack;
public CommandManager(){
currentStack = Collections.synchronizedList(new ArrayList<DrawingPath>());
}
public void addCommand(DrawingPath command){
currentStack.add(command);
}
public void undo (){
final int length = currentStackLength();
if ( length > 0) {
final DrawingPath undoCommand = currentStack.get( length - 1 );
currentStack.remove( length - 1 );
undoCommand.undo();
}
}
public int currentStackLength(){
final int length = currentStack.toArray().length;
return length;
}
public void executeAll( Canvas canvas){
if( currentStack != null ){
synchronized( currentStack ) {
final Iterator<?> i = currentStack.iterator();
while ( i.hasNext() ){
final DrawingPath drawingPath = (DrawingPath) i.next();
drawingPath.draw( canvas );
}
}
}
}
public boolean hasMoreUndo(){
return currentStack.toArray().length > 0;
}
}
DrawingPath.java
package com.pop.digitalsign;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Path;
public class DrawingPath {
public Path path;
public Paint paint;
public void draw(Canvas canvas) {
canvas.drawPath( path, paint );
}
public void undo() {
}
}
main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical"
android:background="#android:color/white" >
<com.pop.digitalsign.DrawingSurface
android:id="#+id/drawingSurface"
android:layout_width="match_parent"
android:layout_height="match_parent"
/>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:gravity="center" >
<Button
android:id="#+id/saveBtn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="saveDrawing"
android:text="#string/save" />
<Button
android:id="#+id/clearBtn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="clearScreen"
android:text="#string/clear" />
</LinearLayout>
</RelativeLayout>

the best suggestion i have is to use this
if (surfaceHolder.getSurface().isValid()) {
Canvas c = surfaceHolder.lockCanvas();
if (first >= 0) {
c.drawARGB(255, 255, 255, 255);
first--;
}
The value of first is 2 you can use what every name you want.
The reason is that the canvas is double buffered so you need to clear both screen by painting it white.
This stops the flickering

canvas.drawColor(Color.TRANSPARENT, PorterDuff.Mode.CLEAR)

In DrawingSurface add this method
public void resetCanvas(){ commandManager.clearAllPath(); }
and call this method, when you need to action for clear..
objectNameofDrawingSurefaceClass.resetCanvas();
add the code in CommandManager
public void clearAllPath(){currentStack.clear(); }
ok..