How to take first touch coordinates and make it constant.
I wanna click something on screen then draw a permanent on first touch and then want to move another circle within the the permanent circle one
hers the code am trying :
public class MainActivity extends Activity implements OnTouchListener {
private float x;
private float y;
static float lasttouchx;
static float lasttouchy;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
MyCustomPanel view = new MyCustomPanel(this);
ViewGroup.LayoutParams params =
new ViewGroup.LayoutParams(LayoutParams.FILL_PARENT,
LayoutParams.FILL_PARENT);
addContentView(view, params);
view.setOnTouchListener(this);
}
private class MyCustomPanel extends View {
public MyCustomPanel(Context context) {
super(context);
}
#Override
public void draw(Canvas canvas) {
super.draw(canvas);
Paint paint = new Paint();
paint.setColor(Color.BLACK);
paint.setStrokeWidth(5);
paint.setTextSize(50);
canvas.drawText(" X : " + (int) x + " Y : " + (int) y, canvas.getWidth() - 500, 200, paint);
paint.setStyle(Paint.Style.FILL);
if((x<=1000&& x>=18)&&(y<=1380&&y>=348)){
paint.setColor(Color.BLUE);
canvas.drawCircle(x, y, 100, paint);
paint.setColor(Color.BLACK);
paint.setStyle(Paint.Style.STROKE);
paint.setStrokeWidth(20);
canvas.drawCircle(lasttouchx, lasttouchy, 500, paint);
}
else{}
}
}
#Override
public boolean onTouch(View v, MotionEvent event) {
x = event.getX();
y = event.getY();
int action = event.getActionMasked();
switch (action){
case MotionEvent.ACTION_DOWN:
lasttouchx = event.getX();
lasttouchy = event.getY();
return false;
}
v.invalidate();
return true;
}
}
Override onTouchEvent(MotionEvent event) and then call event.getX() and event.getY() to get the coordinate positions of where the user touched.
then store value to some variable.
now use these values you want and try replacing to another.
Check stack answer to get touch screen information answer
Related
I need help with this thing
I draw line on canvas and i need to be able to modify the position after it's been drawn. I search and try a lot of things, but no one seems that it works
I want to select one of the ends of the line and dragging them in another position
Can someone give me and advice?
Please try this.In this you can draw and edit the line.
class Drawing extends View{
private Canvas mCanvas = null;
private Path mPath = null;
private Paint mBitmapPaint = null;
private Bitmap mBitmap = null;
private Bitmap bit=null;
private Paint mPaint = null;
private MainActivity baseMainActivity = null;
public interface onDrawingViewSingleTap{
void onDrawingViewTap(float x , float y);
}
public Drawing(Context c) {
super(c);
baseMainActivity=(MainActivity) c;
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setDither(true);
mPaint.setColor(Color.YELLOW);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(6);//This sets the width of signature
Display display =baseMainActivity.getWindowManager().getDefaultDisplay();
mBitmap = Bitmap.createBitmap(display.getWidth(), display.getHeight(), Bitmap.Config.ARGB_8888);// 320*480 // For setting size of screen to draw Bitmap
mPath = new Path();
mBitmapPaint = new Paint(Paint.DITHER_FLAG);
mCanvas = new Canvas(mBitmap);
onDraw(mCanvas);
}
#Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
}
#Override
protected void onDraw(Canvas canvas) {
try{
canvas.drawColor(Color.TRANSPARENT);//Color.WHITE //To change background color of Application
if(bit!=null)
canvas.drawBitmap(bit, 0, 0, mBitmapPaint);
else
canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);
}catch(Exception e){}
if(bit==null)
canvas.drawPath(mPath, mPaint);
bit=null;
}
private float mX, mY;
private void touch_start(float x, float y) {
mPath.reset();
mPath.moveTo(x, y);
mX = x+1;
mY = y+1;
}
private void touch_upline(float x,float y) {
mPath.lineTo(mX, mY);
mCanvas.drawLine(mX, mY, x, y, mPaint);
mPath.reset();
}
#Override
public boolean onTouchEvent(MotionEvent event) {
float x = event.getX();
float y = event.getY();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
touch_start(x, y);
invalidate();
break;
case MotionEvent.ACTION_MOVE:
eraseAll();
touch_upline(x, y);
invalidate();
break;
case MotionEvent.ACTION_UP:
touch_upline(x,y);
invalidate();
break;
}
return true;
}
public void eraseAll()
{
mBitmap.eraseColor(android.graphics.Color.TRANSPARENT);
mCanvas = new Canvas(mBitmap);
}
public class MainActivity extends Activity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
RelativeLayout relativeLayout= (RelativeLayout) (findViewById(R.id.mainLayout));
relativeLayout.addView(new Drawing(this));
}
}
I wanted to draw the custom shape using multiple straight lines. For that, i used the canvas. But I can draw only one line. When I draw second, previous disappears.
My code is given.
public class CanvasBackground extends View {
public Paint paint;
public Context context;
public Canvas canvas;
public ScaleGestureDetector scaleGestureDetector;
float scalfactor = 1f;
boolean isDrawing;
private PointF startPoint, endPoint;
public CanvasBackground(Context context) {
super(context);
this.context = context;
paint = new Paint();
scaleGestureDetector = new ScaleGestureDetector(context, new CanvasScale());
setDrawingCacheEnabled(true);
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
this.canvas = canvas;
paint.setColor(Color.WHITE);
canvas.drawPaint(paint);
canvas.save();
DrawingZoomingCanvas(canvas);
DrawingLine(canvas);
canvas.restore();
Log.e("OnDraw >>>", "CALLING");
}
#Override
public boolean onTouchEvent(MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
startPoint = new PointF(event.getX(), event.getY());
endPoint = new PointF();
isDrawing = true;
break;
case MotionEvent.ACTION_MOVE:
if (isDrawing) {
endPoint.x = event.getX();
endPoint.y = event.getY();
invalidate();
}
break;
case MotionEvent.ACTION_UP:
if (isDrawing) {
endPoint.x = event.getX();
endPoint.y = event.getY();
//isDrawing = false;
invalidate();
}
break;
default:
break;
}
//scaleGestureDetector.onTouchEvent(event);
Log.e("OnTouch >>>", "CALLING" + isDrawing);
return true;
}
//drawing Matrix Canvas With Zoom
private void DrawingZoomingCanvas(Canvas canvas) {
//drawing Matarix
canvas.translate(scalfactor * 10, scalfactor * 10);
canvas.scale(scalfactor, scalfactor);
paint.setColor(Color.rgb(220, 220, 220));
for (int i = 0; i <= canvas.getHeight() * scalfactor; i += 10) {
canvas.drawLine(i, 0, i, canvas.getHeight(), paint);
canvas.drawLine(0, i, canvas.getWidth(), i, paint);
}
}
//drawing a line
private void DrawingLine(Canvas canvas) {
paint = new Paint();
paint.setColor(Color.RED);
paint.setStyle(Paint.Style.STROKE);
paint.setStrokeWidth(2);
paint.setAntiAlias(true);
if (isDrawing)
canvas.drawLine(startPoint.x, startPoint.y, endPoint.x, endPoint.y, paint);
}
private class CanvasScale extends ScaleGestureDetector.SimpleOnScaleGestureListener {
#Override
public boolean onScale(ScaleGestureDetector detector) {
scalfactor *= scaleGestureDetector.getScaleFactor();
scalfactor = Math.max(0.1f, Math.min(scalfactor, 10.0f));
invalidate();
return true;
}
}
}
You are clearing your canvas each time you draw a line, so the previous line will be erased as you draw the new one.
You need to store the previous lines in a bitmap so you can draw these when you draw the new one.
I am new to android programing. I am trying to draw a new bitmap image every time the user touches the screen. With the current code right now, all it does is change where the bitmap is at. It doesn't make a new one. How could I make a new one?? Here is the code:
public class MainDrawingView extends View {
public float eventX;
public float eventY;
public AlertDialog.Builder alertThing;
Context context = getContext();
//Bitmaps
public Bitmap redSquare;
public String x;
public String y;
//Colors
public boolean red = false;
public boolean blue = false;
//Squares
public boolean topRight = false;
public boolean topLeft = false;
public boolean bottomLeft = false;
public boolean bottomRight = false;
public int width = context.getResources().getDisplayMetrics().widthPixels;
public int height = context.getResources().getDisplayMetrics().heightPixels;
public int center = height/2;
public int widthDiv = width/2;
private Paint paint = new Paint();
private Point pointStart = new Point();
private Point pointEnd = new Point();
public MainDrawingView(Context context, AttributeSet attrs){
super(context, attrs);
paint.setAntiAlias(true);
paint.setStrokeWidth(5f);
paint.setColor(Color.BLACK);
paint.setStyle(Paint.Style.STROKE);
paint.setStrokeJoin(Paint.Join.ROUND);
alertThing = new AlertDialog.Builder(context);
//define bitmap
redSquare = BitmapFactory.decodeResource(getResources(), R.drawable.red);
}
#Override
public void onDraw(Canvas canvas){
//canvas.drawPath(path, paint);
canvas.drawLine(pointStart.x, pointStart.y, pointEnd.x, pointEnd.y,paint);
//Makes a straight line go through the center of the screen.
canvas.drawLine(0,height/2.5f, width,height/2.5f,paint);
//Makes a straight line go up and down.
canvas.drawLine(width/2.3f,0, width/2.3f, height,paint);
//Chnages the square colors.
// top left combo
if(topLeft){
if(red){
Toast.makeText(context,"jgjgjgjgjgjgjgjgjjg", Toast.LENGTH_SHORT).show();
new Drawings(redSquare, canvas, eventX, eventY);
}
}
}
#Override
public boolean onTouchEvent(MotionEvent event){
//Gets the coords of the tap
eventX = event.getX();
eventY = event.getY();
int pointX = Math.round(eventX);
int pointY = Math.round(eventY);
x = String.valueOf(eventX);
y = String.valueOf(eventY);
//This is the top left "square"
if(eventY < center && eventX < widthDiv ){
alertThing.setTitle("edit square");
alertThing.setMessage("please choose an option");
alertThing.setPositiveButton("red", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
topLeft = true;
red = true;
invalidate();
}
});
alertThing.setNeutralButton("Chnange color to blue", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
}
});
alertThing.create();
alertThing.show();
}
Toast.makeText(context, "center is :" +x, Toast.LENGTH_SHORT ).show();
switch(event.getAction()){
case MotionEvent.ACTION_DOWN:
//Sets a new starting point
pointStart.set(pointX,pointY);
return true;
case MotionEvent.ACTION_UP:
//Contects the points
pointEnd.set(pointX,pointY);
break;
default:
return false;
}
invalidate();
return true;
}
}
Here is the Drawings class that draws the bitmaps:
public class Drawings {
public Drawings(Bitmap bitmap, Canvas canvas,float x, float y){
canvas.drawBitmap(bitmap, x,y,null);
}
}
You really should see what canvas.drawBitmap does. Of course it changes the position, since the touch position changes too.
You create a new bitmap just like you did it when defining bitmap.
But creating new objects in the onDraw will be very slow.
I wrote code which draws a circle wherever i touch and it will remain within the bigger circle or any shape,if you keep pressing down it will remain there but if you touch up or go out of circle,it will return to centre.But whenever i just hold my touch down i want the smaller circle to remain at boundary when it gets out of bigger circle.
Here's My code:
public class MainActivity extends Activity implements OnTouchListener {
static private float x;
static private float y;
static float lasttouchx;
static float lasttouchy;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
MyCustomPanel view = new MyCustomPanel(this);
ViewGroup.LayoutParams params =
new ViewGroup.LayoutParams(LayoutParams.FILL_PARENT,
LayoutParams.FILL_PARENT);
addContentView(view, params);
view.setOnTouchListener(this);
}
private class MyCustomPanel extends View {
public MyCustomPanel(Context context) {
super(context);
}
#Override
public void draw(Canvas canvas) {
super.draw(canvas);
Paint paint = new Paint();
paint.setStyle(Paint.Style.STROKE);
paint.setStrokeWidth(20);
paint.setAntiAlias(true);
if(lasttouchx!=0&&lasttouchy!=0) {
paint.setColor(Color.BLACK);
canvas.drawCircle(lasttouchx, lasttouchy, 400, paint);
paint.setStrokeWidth(5);
canvas.drawLine(lasttouchx, lasttouchy - 400, lasttouchx, lasttouchy + 400, paint);
canvas.drawLine(lasttouchx- 400, lasttouchy , lasttouchx+400,lasttouchy,paint);
}
else
{}
paint.setColor(Color.YELLOW);
paint.setStrokeWidth(5);
paint.setTextSize(50);
canvas.drawText(" X : " + (int) x + "\n Y : " + (int) y, canvas.getWidth() - 500, 200, paint);
paint.setStyle(Paint.Style.FILL);
if((x<=lasttouchx+410 && x>=lasttouchx-410&&x!=0)&&(y<=lasttouchy+420 && y>=lasttouchy-420&&y!=0)){
paint.setColor(Color.MAGENTA);
canvas.drawCircle(x, y, 70, paint);
}
else if(x!=0&&y!=0){
paint.setColor(Color.RED);
canvas.drawCircle(lasttouchx,lasttouchy, 70, paint);
}
else{}
}
}
#Override
public boolean onTouch(View v, MotionEvent event) {
x = event.getX();
y = event.getY();
int action = event.getActionMasked();
switch (action){
case MotionEvent.ACTION_DOWN:
lasttouchx = event.getX();
lasttouchy = event.getY();
break;
case MotionEvent.ACTION_UP:
x=lasttouchx;
y=lasttouchy;
break;
}
v.invalidate();
return true;
}
}
Edit: Nevermind i solved it here's the new code
public class MainActivity extends Activity implements OnTouchListener {
static private float x;
static private float y;
static float lasttouchx;
static float lasttouchy;
static float boundx;
static float boundy;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
MyCustomPanel view = new MyCustomPanel(this);
ViewGroup.LayoutParams params =
new ViewGroup.LayoutParams(LayoutParams.FILL_PARENT,
LayoutParams.FILL_PARENT);
addContentView(view, params);
view.setOnTouchListener(this);
}
private class MyCustomPanel extends View {
public MyCustomPanel(Context context) {
super(context);
}
#Override
public void draw(Canvas canvas) {
super.draw(canvas);
Paint paint = new Paint();
paint.setStyle(Paint.Style.STROKE);
paint.setStrokeWidth(20);
paint.setAntiAlias(true);
if(lasttouchx!=0&&lasttouchy!=0) {
paint.setColor(Color.BLACK);
canvas.drawCircle(lasttouchx, lasttouchy, 400, paint);
paint.setStrokeWidth(5);
canvas.drawLine(lasttouchx, lasttouchy - 400, lasttouchx, lasttouchy + 400, paint);
canvas.drawLine(lasttouchx- 400, lasttouchy , lasttouchx+400,lasttouchy,paint);
}
else
{}
paint.setColor(Color.YELLOW);
paint.setStrokeWidth(5);
paint.setTextSize(50);
canvas.drawText(" X : " + (int) x + "\n Y : " + (int) y, canvas.getWidth() - 500, 200, paint);
paint.setStyle(Paint.Style.FILL);
if((x<=lasttouchx+410 && x>=lasttouchx-410&&x!=0)&&(y<=lasttouchy+420 && y>=lasttouchy-420&&y!=0)){
paint.setColor(Color.MAGENTA);
canvas.drawCircle(x, y, 70, paint);
}
else if(x!=0&&y!=0){
paint.setColor(Color.RED);
canvas.drawCircle(boundx,boundy, 70, paint);
}
else{}
}
}
#Override
public boolean onTouch(View v, MotionEvent event) {
x = event.getX();
y = event.getY();
int action = event.getActionMasked();
switch (action){
case MotionEvent.ACTION_DOWN:
lasttouchx = event.getX();
lasttouchy = event.getY();
break;
case MotionEvent.ACTION_UP:
x=lasttouchx;
y=lasttouchy;
break;
}
if((x<=lasttouchx+409 && x>=lasttouchx-409&&x!=0)&&(y<=lasttouchy+419 && y>=lasttouchy-419&&y!=0)){
boundx = event.getX();
boundy = event.getY();
}
v.invalidate();
return true;
}
}
Ok i solved it heres the code:
public class MainActivity extends Activity implements OnTouchListener {
static private float x;
static private float y;
static float lasttouchx;
static float lasttouchy;
static float boundx;
static float boundy;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
MyCustomPanel view = new MyCustomPanel(this);
ViewGroup.LayoutParams params =
new ViewGroup.LayoutParams(LayoutParams.FILL_PARENT,
LayoutParams.FILL_PARENT);
addContentView(view, params);
view.setOnTouchListener(this);
}
private class MyCustomPanel extends View {
public MyCustomPanel(Context context) {
super(context);
}
#Override
public void draw(Canvas canvas) {
super.draw(canvas);
Paint paint = new Paint();
paint.setStyle(Paint.Style.STROKE);
paint.setStrokeWidth(20);
paint.setAntiAlias(true);
if(lasttouchx!=0&&lasttouchy!=0) {
paint.setColor(Color.BLACK);
canvas.drawCircle(lasttouchx, lasttouchy, 400, paint);
paint.setStrokeWidth(5);
canvas.drawLine(lasttouchx, lasttouchy - 400, lasttouchx, lasttouchy + 400, paint);
canvas.drawLine(lasttouchx- 400, lasttouchy , lasttouchx+400,lasttouchy,paint);
}
else
{}
paint.setColor(Color.YELLOW);
paint.setStrokeWidth(5);
paint.setTextSize(50);
canvas.drawText(" X : " + (int) x + "\n Y : " + (int) y, canvas.getWidth() - 500, 200, paint);
paint.setStyle(Paint.Style.FILL);
if((x<=lasttouchx+410 && x>=lasttouchx-410&&x!=0)&&(y<=lasttouchy+420 && y>=lasttouchy-420&&y!=0)){
paint.setColor(Color.MAGENTA);
canvas.drawCircle(x, y, 70, paint);
}
else if(x!=0&&y!=0){
paint.setColor(Color.RED);
canvas.drawCircle(boundx,boundy, 70, paint);
}
else{}
}
}
#Override
public boolean onTouch(View v, MotionEvent event) {
x = event.getX();
y = event.getY();
int action = event.getActionMasked();
switch (action){
case MotionEvent.ACTION_DOWN:
lasttouchx = event.getX();
lasttouchy = event.getY();
break;
case MotionEvent.ACTION_UP:
x=lasttouchx;
y=lasttouchy;
break;
}
if((x<=lasttouchx+409 && x>=lasttouchx-409&&x!=0)&&(y<=lasttouchy+419 && y>=lasttouchy-419&&y!=0)){
boundx = event.getX();
boundy = event.getY();
}
v.invalidate();
return true;
}
}
Im making a basic app to test making paths.
So I got the paths to work, but when I am in the emulator and begin a path it starts the path about inch below from where I clicked.
Besides from the path being a inch off below, it will follow my mouse and make a path but always from a inch below where the mouse is.
This is my code:
public class Paths extends Activity {
Path newPath = new Path();
Paint paint = new Paint();
Canvas canvas = new Canvas();
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main_paths);
}
public boolean onTouchEvent(MotionEvent event) {
LinearLayout relative = (LinearLayout) findViewById(R.id.drawing_view2);
float x = event.getRawX();
float y = event.getRawY();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
newPath.moveTo(x, y);
relative.addView(new DrawView2(relative.getContext(), newPath));
return true;
case MotionEvent.ACTION_MOVE:
newPath.lineTo(x, y);
break;
case MotionEvent.ACTION_UP:
default:
return false;
}
relative.invalidate();
return true;
}
This is the java class that handles the paint and canvas objects.
private final Path path;
private final Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
public DrawView2(Context context, Path path) {
super(context);
int mycolor = Color.parseColor("#6633CC");
paint.setAntiAlias(true);
paint.setDither(true);
paint.setColor(mycolor);
paint.setStyle(Paint.Style.STROKE);
paint.setStrokeJoin(Paint.Join.ROUND);
paint.setStrokeCap(Paint.Cap.ROUND);
paint.setStrokeWidth(8f);
this.path = path;
}
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
canvas.drawPath(path, paint);
}
and my layout file
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/drawing_view2"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#33FF99"
You are getting coordinates with
float x = event.getRawX();
float y = event.getRawY();
Instead of this, try that:
float x = event.getX();
float y = event.getY();