I've tried debugging with messages and stuff but the only value i get from event.getAction() is 0 ... which i believe is ACTION_DOWN why dont i detect ACTION_MOVE or ACTION_UP??
package com.andrewxd.test01;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.view.MotionEvent;
import android.view.View;
public class Game extends View {
private Bitmap enemy;
private Enemy enemyN;
private Paint paint;
private float x,y;
public Game(Context context) {
super(context);
enemy = BitmapFactory.decodeResource(getResources(), R.drawable.enemy);
enemy = Bitmap.createScaledBitmap(enemy, 300 , 300, false);
enemyN = new Enemy(10, 10, enemy);
paint = new Paint();
x = 0;
y = 0;
}
#Override
protected void onDraw(Canvas canvas){
canvas.drawRect(x, y, 50, 50, paint);
}
#Override
public boolean onTouchEvent(MotionEvent event){
super.onTouchEvent(event);
if(event.getAction() == MotionEvent.ACTION_DOWN){
x = event.getX();
y = event.getY();
invalidate();
} else if(event.getAction() == MotionEvent.ACTION_MOVE){
x = event.getX();
y = event.getY();
invalidate();
}
return false;
}
}
Am I doing something wrong? or is this supposed to work like this? And if this is supposed to be like this where do i detect touch movement
It's because you're returning false at the end of the onTouchEvent. When you return false, you are saying that your View can not handle any more touch events so the events will no longer be sent to the View. If you want to receive MOVE and UP events, then you need to return true.
Related
This is my first question here! I hope that you can help me!
I'm explain:
I'm trying to develop an app like a paint in android studio to work with Paint,Canvas,and this class...
I have a class call Lienzo.java; This is the code of my class:
package com.example.pedro.paint;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.support.annotation.Nullable;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.graphics.Path;
/**
* Created by Pedro on 26/02/2018.
*/
public class Lienzo extends View {
//PATH TO DRAW THE LINES
private Path drawPath;
//PAINT DRAWING AND PAINT CANVAS
private Paint drawPaint,canvasPaint;
//COLOR INITIAL
private int paintColor=0xFFFF0000;
//CANVAS
private Canvas drawCanvas;
//CANVAS TO SAVE
private Bitmap canvasBitmap;
public Lienzo(Context context, #Nullable AttributeSet attrs) {
super(context, attrs);
setupDrawing();
}
private void setupDrawing(){
//CONFIGURATION AREA TO DRAW
drawPath = new Path();
drawPaint=new Paint();
drawPaint.setColor(paintColor);
drawPaint.setAntiAlias(true);
drawPaint.setStrokeWidth(20);
drawPaint.setStyle(Paint.Style.STROKE);
drawPaint.setStrokeJoin(Paint.Join.ROUND);
drawPaint.setStrokeCap(Paint.Cap.ROUND);
canvasPaint= new Paint(Paint.DITHER_FLAG);
}
//ASIGN SIZE TO VIEW
#Override
protected void onSizeChanged(int w, int h,int oldw, int oldh){
super.onSizeChanged(w,h,oldw,oldh);
canvasBitmap=Bitmap.createBitmap(w,h,Bitmap.Config.ARGB_8888);
drawCanvas=new Canvas(canvasBitmap);
}
//PAINT THE VIEW.CALL BY ONTHOUCHEVENT
#Override
protected void onDraw(Canvas canvas){
canvas.drawBitmap(canvasBitmap,0,0,canvasPaint);
canvas.drawPath(drawPath,drawPaint);
}
//REGISTER USER TOUCH
public boolean OnTouchEvent(MotionEvent event)
{
float touchX =event.getX();
float touchY=event.getY();
switch (event.getAction())
{
case MotionEvent.ACTION_DOWN:
drawPath.moveTo(touchX,touchY);
break;
case MotionEvent.ACTION_MOVE:
drawPath.lineTo(touchX,touchY);
break;
case MotionEvent.ACTION_UP:
drawPath.lineTo(touchX,touchY);
drawCanvas.drawPath(drawPath,drawPaint);
drawPath.reset();
break;
default:
return false;
}
//REPAINT
invalidate();
return true;
}
}
I have no error but I try to paint but do nothing.
This is a copy of an example.The original https://www.youtube.com/watch?v=GAr_agEokr8 works but my code,its equal and dont work.
Anybody knows why?
Thanks and regards!
OnTouchEvent change to onTouchEvent and add #Override
I am LibGdx Newbie, and trying to make my iceCream image touchable.
I like to know how to set the input-process(by touch on screen).
Do I need to make another class? When I try to implements the input-process to
my Prac1 class, JAVA doesn't allow me to implements without changing the class abstract. To be specific, I like to make it whenever the user touch the image
,it counts the number of touch. Here is my code and Thank you for help.
import com.badlogic.gdx.ApplicationAdapter;
import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.graphics.GL20;
import com.badlogic.gdx.graphics.OrthographicCamera;
import com.badlogic.gdx.graphics.Texture;
import com.badlogic.gdx.graphics.g2d.SpriteBatch;
public class Prac1 extends ApplicationAdapter {
int w,h,tw,th =0;
OrthographicCamera camera;
SpriteBatch batch;
Texture img;
#Override
public void create () {
w = Gdx.graphics.getWidth();
h = Gdx.graphics.getHeight();
camera = new OrthographicCamera(w, h);
camera.position.set(w/2, h/2, 0);
camera.update();
batch = new SpriteBatch();
img = new Texture(Gdx.files.internal("iceCream.png"));
tw = img.getWidth();
th = img.getHeight();
}
#Override
public void render () {
Gdx.gl.glClearColor(0, 0, 0, 1);
Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
batch.begin();
batch.draw(img, camera.position.x - (tw/2), camera.position.y - (th/2));
batch.end();
}
}
You can use InputProcessor to handle user input.
Like this:-
import com.badlogic.gdx.ApplicationAdapter;
import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.InputAdapter;
import com.badlogic.gdx.graphics.GL20;
import com.badlogic.gdx.graphics.OrthographicCamera;
import com.badlogic.gdx.graphics.Texture;
import com.badlogic.gdx.graphics.g2d.Sprite;
import com.badlogic.gdx.graphics.g2d.SpriteBatch;
public class Prac1 extends ApplicationAdapter {
float w,h,tw,th =0;
OrthographicCamera camera;
SpriteBatch batch;
Sprite img;
#Override
public void create () {
w = Gdx.graphics.getWidth();
h = Gdx.graphics.getHeight();
camera = new OrthographicCamera(w, h);
camera.position.set(w/2, h/2, 0);
camera.update();
batch = new SpriteBatch();
img = new Sprite(new Texture(Gdx.files.internal("iceCream.png")));
tw = img.getWidth();
th = img.getHeight();
img.setBounds( camera.position.x - (tw/2), camera.position.y - (th/2),tw,th);
Gdx.input.setInputProcessor(new InputAdapter(){
#Override
public boolean touchDown(int screenX, int screenY, int pointer, int button) {
if(img.getBoundingRectangle().contains(screenX, screenY))
System.out.println("Image Clicked");
return true;
}
});
}
#Override
public void render () {
Gdx.gl.glClearColor(0, 0, 0, 1);
Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
batch.begin();
img.draw(batch);
batch.end();
}
}
replace this code with your code you can easily understand what is happening here.
your can also implement GestureListener to handle gesture events.
Since you need to get touch events from image, you can do that with Stage and Actors. You'll need to create a Stage and Image with your texture, then add Touchable attributes:
iceCreamImg.setTouchable(Touchable.enabled);
iceCreamImg.addListener(new InputListener() {
public boolean touchDown (InputEvent event, float x, float y, int pointer, int button) {
Gdx.app.debug(TAG, "touchDown()");
// must return true for touchUp event to occur
return true;
}
public void touchUp (InputEvent event, float x, float y, int pointer, int button) {
Gdx.app.debug(TAG, "touchUp()");
}
and add Image to the stage. In render method you should add:
stage.act();
stage.draw();
and also set input processor for your stage with
Gdx.input.setInputProcessor(stage);
If you want to use both ApplicationAdapter and InputProcessor in you Class, you have to use the interfaces rather than the abstract: Change you class signature to Prac1 implements ApplicationListener, InputProcessor
Check here for a complete tutorial:
http://www.gamefromscratch.com/post/2013/10/24/LibGDX-Tutorial-5-Handling-Input-Touch-and-gestures.aspx
This is my first time using Canvas in Android.
I am creating an app that would display circles at certain positions on the screen one at a time (positions are selected randomly). New circle should be drawn after the previous one was selected/touched, and the previous one should disappear.
I have some ideas about it: to keep an arraylist of Point objects(each object contains x,y coordinate of the centre of the circle) and randomly select one each time the circle is drawn on the screen. So first I am populating an array of points. I also know how to randomly select the element from arraylist.
My biggest confustion is how to connect onDraw and onTouchEvent methods with each other? I know I should check if the circle was selected and only then draw a new circle at the randomly selected position, but I m not sure how to make a call for onDraw() method from the onTouchEvent...
Could you please help with this issue?
My code is below:
package com.example.researcher.heatmap;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Point;
import android.graphics.PorterDuff;
import android.graphics.drawable.Drawable;
import android.text.TextPaint;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import java.util.ArrayList;
import java.util.List;
/**
* TODO: document your custom view class.
*/
public class MyView extends View {
Paint paint;
ArrayList<Point> points = new ArrayList<>();
public MyView(Context context) {
super(context);
init();
}
public MyView(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
public MyView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
init();
}
private void init() {
// Load attributes
paint = new Paint();
paint.setColor(Color.BLUE);
paint.setStrokeWidth(5);
paint.setStyle(Paint.Style.STROKE);
populateArrayList();
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
paint.setStyle(Paint.Style.STROKE);
canvas.drawColor(Color.WHITE);
int i=1; // should be random, will randomize later
for(Point p: points) {
p.x = points.get(i).x;
p.y = points.get(i).y;
canvas.drawCircle(p.x, p.y, 50, paint);
}
}
#Override
public boolean onTouchEvent(MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
int i=1;
for(Point p: points) {
Canvas canvas = new Canvas();
p.x = points.get(i).x;
p.y = points.get(i).y;
canvas.drawCircle(p.x, p.y, 50, paint);
}
postInvalidate();
case MotionEvent.ACTION_MOVE:
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_CANCEL: {
break;
}
}
postInvalidate();
return true;
}
public void populateArrayList(){
points.clear();
points.add(new Point(120, 120));
points.add(new Point(150, 320));
points.add(new Point(280, 200));
}
}
Thank you Chris for your help! I really appreciate it.
Here is my solution if someone will need it for reference
package com.example.researcher.heatmap;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.Point;
import android.graphics.PorterDuff;
import android.graphics.drawable.Drawable;
import android.text.TextPaint;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;
/**
* TODO: document your custom view class.
*/
public class MyView extends View {
Paint paint;
ArrayList<Point> points = new ArrayList<>();
private int pointsPos = 0; //Which point we will be drawing
public float x;
public float y;
public int radius = 150;
public MyView(Context context) {
super(context);
x = this.getX();
y = this.getY();
init();
}
public MyView(Context context, AttributeSet attrs) {
super(context, attrs);
x = this.getX();
y = this.getY();
init();
}
public MyView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
x = this.getX();
y = this.getY();
init();
}
private void init() {
// Load attributes
paint = new Paint();
paint.setColor(Color.BLUE);
paint.setStrokeWidth(5);
paint.setStyle(Paint.Style.STROKE);
populateArrayList();
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
paint.setStyle(Paint.Style.STROKE);
canvas.drawColor(Color.WHITE);
canvas.drawCircle(points.get(pointsPos).x, points.get(pointsPos).y, radius, paint);
}
#Override
public boolean onTouchEvent(MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
case MotionEvent.ACTION_MOVE:
case MotionEvent.ACTION_UP:
//Check if the point press is within the circle
if(contains(event, points.get(pointsPos))){
Random r = new Random(System.nanoTime());
pointsPos = r.nextInt(points.size());; //between 0 and points.length
postInvalidate();
}
case MotionEvent.ACTION_CANCEL: {
break;
}
}
postInvalidate();
return true;
}
private boolean contains(MotionEvent event, Point point) {
float xTouch = event.getX();
float yTouch = event.getY();
if ((xTouch - point.x) * (xTouch - point.x) + (yTouch - point.y) * (yTouch - point.y) <= radius * radius) {
return true;
}
else {
return false;
}
}
public void populateArrayList(){
points.clear();
points.add(new Point(220, 1020));
points.add(new Point(550, 320));
points.add(new Point(780, 500));
}
}
Class var
private int state = 0 //0 normal, 1 new circle
private int pointPos = 0; //Which point we will be drawing
onDraw was overwriting the x/y of all your other points
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
paint.setStyle(Paint.Style.STROKE);
canvas.drawColor(Color.WHITE);
if(state == 1){
pointPos = random(); //between 0 and points.length
state = 0;
}
canvas.drawCircle(points.get(pointsPos).x, points.get(pointsPos).y, 50, paint);
}
onTouchEvent: Drawing should only be done on the ondraw, use flags/states to keep track of what you should be doing on the next draw call
#Override
public boolean onTouchEvent(MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
//Though these days this is usually done on the up event
//Check if the point press is within the circle
if(contains(event, points.get(pointPos))){
state = 1;
postInvalidate();
}
case MotionEvent.ACTION_MOVE:
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_CANCEL: {
break;
}
}
postInvalidate();
return true;
}
I have been making a paint app for android with the ability to choose different colors.
my task is almost complete. yet there is cetain lag in my app. At start it works fine but after some lines it starts giving straight lines instead of curves and lags in usage....
This is the code for my DrawIt:
package app.paintit;
import java.util.ArrayList;
import java.util.LinkedList;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.view.MotionEvent;
import android.view.View;
public class DrawIt extends View{
float x,y;
Paint paint;
int count1=0,count2=0;
ArrayList<Lines> lines = new ArrayList<Lines>();
public int color= 0xFFFFFF;
Lines l;
Path path;
public DrawIt(Context context) {
super(context);
// TODO Auto-generated constructor stub
x=0;y=0;
paint=new Paint();
path = new Path();
paint.setAntiAlias(true);
paint.setStrokeWidth(2);
paint.setStyle(Paint.Style.STROKE);
paint.setStrokeJoin(Paint.Join.ROUND);
setOnTouchListener(new OnTouchListener() {
#Override
public boolean onTouch(View arg0, MotionEvent event) {
// TODO Auto-generated method stub
if(event.getAction() == MotionEvent.ACTION_DOWN){
l = new Lines();
l.color = color;
l.xCoordinate = new ArrayList<Float>();
l.xCoordinate.add(event.getX());
l.yCoordinate = new ArrayList<Float>();
l.yCoordinate.add(event.getY());
lines.add(l);
}
else if(event.getAction() == MotionEvent.ACTION_MOVE)
{
l.color = color;
l.xCoordinate.add(event.getX());
l.yCoordinate.add(event.getY());
lines.add(l);
}
invalidate();
return true;
}
});
}
#Override
protected void onDraw(final Canvas canvas) {
// TODO Auto-generated method stub
super.onDraw(canvas);
canvas.drawColor(Color.BLACK);
Lines p,q;
float nowX,nowY,prevX=0,prevY=0;
for(int j=0;j<lines.size();j++){
p = lines.get(j);
Path path1=new Path();
paint.setColor(p.color);
path1.moveTo(p.xCoordinate.get(0), p.yCoordinate.get(0));
for(int i=1;i<p.xCoordinate.size()-1;i++){
float midX=(p.xCoordinate.get(i)+p.xCoordinate.get(i-1))/2;
float midY=(p.yCoordinate.get(i)+p.yCoordinate.get(i-1))/2;
path1.quadTo(p.xCoordinate.get(i-1), p.yCoordinate.get(i-1), midX, midY);
canvas.drawPath(path1, paint);
}
}
}
}
The code for Lines.java which holds the lists that help in maintaining different colors is :
package app.paintit;
import java.util.ArrayList;
import java.util.LinkedList;
import android.graphics.Color;
public class Lines {
ArrayList<Float> xCoordinate;
ArrayList<Float> yCoordinate;
int color;
}
Please help me how to reduce the lag and the straight lines happening after some shapes are drawn perfectly.
Hi, I have recently started trying to make android apps
and have currently made a few simple ones, but, I am still really confused with the touch methods.
What I'm trying to do is: When your finger is held down on the screen, x increments, but it stops when you release your finger. The problem is that I can't find any method or any way of doing this.
Here is my code:
import java.util.Timer;
import java.util.TimerTask;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.view.MotionEvent;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
public class zombView extends SurfaceView{
private Bitmap bmp, grass, joystick;
private SurfaceHolder holder;
Timer t = new Timer();
float x = 0, y = 0;
boolean forward;
public zombView(Context context) {
super(context);
holder = getHolder();
holder.addCallback(new SurfaceHolder.Callback() {
#Override
public void surfaceDestroyed(SurfaceHolder holder) {
}
#Override
public void surfaceCreated(final SurfaceHolder holder) {
t.scheduleAtFixedRate(new TimerTask(){
public void run(){
Canvas c = holder.lockCanvas(null);
onDraw(c);
holder.unlockCanvasAndPost(c);
if(forward == true){
x++;
}
}
},200,200);
}
#Override
public void surfaceChanged(SurfaceHolder holder, int format,
int width, int height) {
}
});
bmp = BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher);
grass = BitmapFactory.decodeResource(getResources(), R.drawable.grassland);
joystick = BitmapFactory.decodeResource(getResources(), R.drawable.joystic);
}
#Override
protected void onDraw(Canvas canvas) {
canvas.drawColor(Color.BLACK);
canvas.drawBitmap(grass, getWidth() - getWidth(), getHeight() - getHeight(), null);
canvas.drawBitmap(joystick, getWidth() - getWidth(),joystick.getHeight(), null);
canvas.drawBitmap(bmp, x, y, null);
}
#Override
public boolean onTouchEvent(MotionEvent event) {
if(event.getX() > 10 && event.getX() < 1000){
if(event.getY() > 10 && event.getY() < 1000){
x++;
}
}
return super.onTouchEvent(event);
}
}
The MotionEvent class has a getAction method, which specifies what kind of event did your onTouchEvent method has just received. There are three actions that you will use more often:
ACTION_DOWN, which tells you that the user has just put his finger on the screen;
ACTION_MOVE, which tells that the user is still holding his finger on the screen;
ACTION_UP, which tells that the user has taken his finger off the screen.
Depending on what kind of event has just been acquired by your listener you can change the behavior of your code. For more information check the documentation. Hope this helps.