Как создать изменяемый размер прямоугольника с событиями касания пользователя на Android?
Я хочу создать прямоугольную фигуру, размер которой будет изменяться с помощью прикосновений пользователя. Ниже изображение хороший пример того, что я хочу сделать:
Есть ли такой пример? Что мне нужно изучить, чтобы реализовать это?
Заранее спасибо,
5 ответов
Решение
Для реализации пользовательского представления вы извлекаете класс из View:) Override onDraw() для внешности, переопределить onTouchEvent() для обработки ввода. Обратите внимание, что в Android вы не можете рисовать на внешнем виде onDraw(); если вы хотите обновить вид, позвоните invalidate(),
Вы можете реализовать перетаскиваемые углы как отдельные виды. Для внешнего вида, просто используйте готовые изображения (не стесняйтесь извлечь из ImageView). Перетаскивание реализовано как перемещение вашего вида в ответ на сенсорные события. RelativeLayout Ваш друг для произвольного представления позиции.
Вы можете добавить домашние виды к макету; просто перейдите к редактированию XML и введите <com.mypackage.MyViewClass> элемент.
Ответ Чинтана Ратода был отличным решением, но что-то не так, когда он рисует прямоугольник. Я просто редактирую несколько строк кода, чтобы он правильно работал с сенсорным событием пользователя. Теперь вы можете добавить этот вид в макет, а затем нажать, чтобы нарисовать.
import java.util.ArrayList;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Point;
import android.graphics.drawable.BitmapDrawable;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import com.ihnel.englishpronounciation.R;
public class DrawView extends View {
Point[] points = new Point[4];
/**
* point1 and point 3 are of same group and same as point 2 and point4
*/
int groupId = -1;
private ArrayList<ColorBall> colorballs = new ArrayList<ColorBall>();
// array that holds the balls
private int balID = 0;
// variable to know what ball is being dragged
Paint paint;
Canvas canvas;
public DrawView(Context context) {
super(context);
paint = new Paint();
setFocusable(true); // necessary for getting the touch events
canvas = new Canvas();
}
public DrawView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
public DrawView(Context context, AttributeSet attrs) {
super(context, attrs);
paint = new Paint();
setFocusable(true); // necessary for getting the touch events
canvas = new Canvas();
}
// the method that draws the balls
@Override
protected void onDraw(Canvas canvas) {
if(points[3]==null) //point4 null when user did not touch and move on screen.
return;
int left, top, right, bottom;
left = points[0].x;
top = points[0].y;
right = points[0].x;
bottom = points[0].y;
for (int i = 1; i < points.length; i++) {
left = left > points[i].x ? points[i].x:left;
top = top > points[i].y ? points[i].y:top;
right = right < points[i].x ? points[i].x:right;
bottom = bottom < points[i].y ? points[i].y:bottom;
}
paint.setAntiAlias(true);
paint.setDither(true);
paint.setStrokeJoin(Paint.Join.ROUND);
paint.setStrokeWidth(5);
//draw stroke
paint.setStyle(Paint.Style.STROKE);
paint.setColor(Color.parseColor("#AADB1255"));
paint.setStrokeWidth(2);
canvas.drawRect(
left + colorballs.get(0).getWidthOfBall() / 2,
top + colorballs.get(0).getWidthOfBall() / 2,
right + colorballs.get(2).getWidthOfBall() / 2,
bottom + colorballs.get(2).getWidthOfBall() / 2, paint);
//fill the rectangle
paint.setStyle(Paint.Style.FILL);
paint.setColor(Color.parseColor("#55DB1255"));
paint.setStrokeWidth(0);
canvas.drawRect(
left + colorballs.get(0).getWidthOfBall() / 2,
top + colorballs.get(0).getWidthOfBall() / 2,
right + colorballs.get(2).getWidthOfBall() / 2,
bottom + colorballs.get(2).getWidthOfBall() / 2, paint);
//draw the corners
BitmapDrawable bitmap = new BitmapDrawable();
// draw the balls on the canvas
paint.setColor(Color.BLUE);
paint.setTextSize(18);
paint.setStrokeWidth(0);
for (int i =0; i < colorballs.size(); i ++) {
ColorBall ball = colorballs.get(i);
canvas.drawBitmap(ball.getBitmap(), ball.getX(), ball.getY(),
paint);
canvas.drawText("" + (i+1), ball.getX(), ball.getY(), paint);
}
}
// events when touching the screen
public boolean onTouchEvent(MotionEvent event) {
int eventaction = event.getAction();
int X = (int) event.getX();
int Y = (int) event.getY();
switch (eventaction) {
case MotionEvent.ACTION_DOWN: // touch down so check if the finger is on
// a ball
if (points[0] == null) {
//initialize rectangle.
points[0] = new Point();
points[0].x = X;
points[0].y = Y;
points[1] = new Point();
points[1].x = X;
points[1].y = Y + 30;
points[2] = new Point();
points[2].x = X + 30;
points[2].y = Y + 30;
points[3] = new Point();
points[3].x = X +30;
points[3].y = Y;
balID = 2;
groupId = 1;
// declare each ball with the ColorBall class
for (Point pt : points) {
colorballs.add(new ColorBall(getContext(), R.drawable.ic_circle, pt));
}
} else {
//resize rectangle
balID = -1;
groupId = -1;
for (int i = colorballs.size()-1; i>=0; i--) {
ColorBall ball = colorballs.get(i);
// check if inside the bounds of the ball (circle)
// get the center for the ball
int centerX = ball.getX() + ball.getWidthOfBall();
int centerY = ball.getY() + ball.getHeightOfBall();
paint.setColor(Color.CYAN);
// calculate the radius from the touch to the center of the
// ball
double radCircle = Math
.sqrt((double) (((centerX - X) * (centerX - X)) + (centerY - Y)
* (centerY - Y)));
if (radCircle < ball.getWidthOfBall()) {
balID = ball.getID();
if (balID == 1 || balID == 3) {
groupId = 2;
} else {
groupId = 1;
}
invalidate();
break;
}
invalidate();
}
}
break;
case MotionEvent.ACTION_MOVE: // touch drag with the ball
if (balID > -1) {
// move the balls the same as the finger
colorballs.get(balID).setX(X);
colorballs.get(balID).setY(Y);
paint.setColor(Color.CYAN);
if (groupId == 1) {
colorballs.get(1).setX(colorballs.get(0).getX());
colorballs.get(1).setY(colorballs.get(2).getY());
colorballs.get(3).setX(colorballs.get(2).getX());
colorballs.get(3).setY(colorballs.get(0).getY());
} else {
colorballs.get(0).setX(colorballs.get(1).getX());
colorballs.get(0).setY(colorballs.get(3).getY());
colorballs.get(2).setX(colorballs.get(3).getX());
colorballs.get(2).setY(colorballs.get(1).getY());
}
invalidate();
}
break;
case MotionEvent.ACTION_UP:
// touch drop - just do things here after dropping
break;
}
// redraw the canvas
invalidate();
return true;
}
public static class ColorBall {
Bitmap bitmap;
Context mContext;
Point point;
int id;
static int count = 0;
public ColorBall(Context context, int resourceId, Point point) {
this.id = count++;
bitmap = BitmapFactory.decodeResource(context.getResources(),
resourceId);
mContext = context;
this.point = point;
}
public int getWidthOfBall() {
return bitmap.getWidth();
}
public int getHeightOfBall() {
return bitmap.getHeight();
}
public Bitmap getBitmap() {
return bitmap;
}
public int getX() {
return point.x;
}
public int getY() {
return point.y;
}
public int getID() {
return id;
}
public void setX(int x) {
point.x = x;
}
public void setY(int y) {
point.y = y;
}
}
}
Следующий код должен нарисовать прямоугольник на сенсорной основе.
import java.util.ArrayList;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Point;
import android.graphics.drawable.BitmapDrawable;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import com.common.Utils;
import com.example.rectangleoverlay.R;
public class DrawView extends View {
Point point1, point3;
Point point2, point4;
/**
* point1 and point 3 are of same group and same as point 2 and point4
*/
int groupId = -1;
private ArrayList<ColorBall> colorballs = new ArrayList<ColorBall>();
// array that holds the balls
private int balID = 0;
// variable to know what ball is being dragged
Paint paint;
Canvas canvas;
public DrawView(Context context) {
super(context);
paint = new Paint();
setFocusable(true); // necessary for getting the touch events
canvas = new Canvas();
// setting the start point for the balls
point1 = new Point();
point1.x = 50;
point1.y = 20;
point2 = new Point();
point2.x = 150;
point2.y = 20;
point3 = new Point();
point3.x = 150;
point3.y = 120;
point4 = new Point();
point4.x = 50;
point4.y = 120;
// declare each ball with the ColorBall class
colorballs.add(new ColorBall(context, R.drawable.gray_circle, point1));
colorballs.add(new ColorBall(context, R.drawable.gray_circle, point2));
colorballs.add(new ColorBall(context, R.drawable.gray_circle, point3));
colorballs.add(new ColorBall(context, R.drawable.gray_circle, point4));
}
public DrawView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
public DrawView(Context context, AttributeSet attrs) {
super(context, attrs);
paint = new Paint();
setFocusable(true); // necessary for getting the touch events
canvas = new Canvas();
// setting the start point for the balls
point1 = new Point();
point1.x = 50;
point1.y = 20;
point2 = new Point();
point2.x = 150;
point2.y = 20;
point3 = new Point();
point3.x = 150;
point3.y = 120;
point4 = new Point();
point4.x = 50;
point4.y = 120;
// declare each ball with the ColorBall class
colorballs.add(new ColorBall(context, R.drawable.gray_circle, point1));
colorballs.add(new ColorBall(context, R.drawable.gray_circle, point2));
colorballs.add(new ColorBall(context, R.drawable.gray_circle, point3));
colorballs.add(new ColorBall(context, R.drawable.gray_circle, point4));
}
// the method that draws the balls
@Override
protected void onDraw(Canvas canvas) {
// canvas.drawColor(0xFFCCCCCC); //if you want another background color
paint.setAntiAlias(true);
paint.setDither(true);
paint.setColor(Color.parseColor("#55000000"));
paint.setStyle(Paint.Style.FILL);
paint.setStrokeJoin(Paint.Join.ROUND);
// mPaint.setStrokeCap(Paint.Cap.ROUND);
paint.setStrokeWidth(5);
canvas.drawPaint(paint);
paint.setColor(Color.parseColor("#55FFFFFF"));
if (groupId == 1) {
canvas.drawRect(point1.x + colorballs.get(0).getWidthOfBall() / 2,
point3.y + colorballs.get(2).getWidthOfBall() / 2, point3.x
+ colorballs.get(2).getWidthOfBall() / 2, point1.y
+ colorballs.get(0).getWidthOfBall() / 2, paint);
} else {
canvas.drawRect(point2.x + colorballs.get(1).getWidthOfBall() / 2,
point4.y + colorballs.get(3).getWidthOfBall() / 2, point4.x
+ colorballs.get(3).getWidthOfBall() / 2, point2.y
+ colorballs.get(1).getWidthOfBall() / 2, paint);
}
BitmapDrawable mBitmap;
mBitmap = new BitmapDrawable();
// draw the balls on the canvas
for (ColorBall ball : colorballs) {
canvas.drawBitmap(ball.getBitmap(), ball.getX(), ball.getY(),
new Paint());
}
}
// events when touching the screen
public boolean onTouchEvent(MotionEvent event) {
int eventaction = event.getAction();
int X = (int) event.getX();
int Y = (int) event.getY();
switch (eventaction) {
case MotionEvent.ACTION_DOWN: // touch down so check if the finger is on
// a ball
balID = -1;
groupId = -1;
for (ColorBall ball : colorballs) {
// check if inside the bounds of the ball (circle)
// get the center for the ball
Utils.logd("Id : " + ball.getID());
Utils.logd("getX : " + ball.getX() + " getY() : " + ball.getY());
int centerX = ball.getX() + ball.getWidthOfBall();
int centerY = ball.getY() + ball.getHeightOfBall();
paint.setColor(Color.CYAN);
// calculate the radius from the touch to the center of the ball
double radCircle = Math
.sqrt((double) (((centerX - X) * (centerX - X)) + (centerY - Y)
* (centerY - Y)));
Utils.logd("X : " + X + " Y : " + Y + " centerX : " + centerX
+ " CenterY : " + centerY + " radCircle : " + radCircle);
if (radCircle < ball.getWidthOfBall()) {
balID = ball.getID();
Utils.logd("Selected ball : " + balID);
if (balID == 1 || balID == 3) {
groupId = 2;
canvas.drawRect(point1.x, point3.y, point3.x, point1.y,
paint);
} else {
groupId = 1;
canvas.drawRect(point2.x, point4.y, point4.x, point2.y,
paint);
}
invalidate();
break;
}
invalidate();
}
break;
case MotionEvent.ACTION_MOVE: // touch drag with the ball
// move the balls the same as the finger
if (balID > -1) {
Utils.logd("Moving Ball : " + balID);
colorballs.get(balID).setX(X);
colorballs.get(balID).setY(Y);
paint.setColor(Color.CYAN);
if (groupId == 1) {
colorballs.get(1).setX(colorballs.get(0).getX());
colorballs.get(1).setY(colorballs.get(2).getY());
colorballs.get(3).setX(colorballs.get(2).getX());
colorballs.get(3).setY(colorballs.get(0).getY());
canvas.drawRect(point1.x, point3.y, point3.x, point1.y,
paint);
} else {
colorballs.get(0).setX(colorballs.get(1).getX());
colorballs.get(0).setY(colorballs.get(3).getY());
colorballs.get(2).setX(colorballs.get(3).getX());
colorballs.get(2).setY(colorballs.get(1).getY());
canvas.drawRect(point2.x, point4.y, point4.x, point2.y,
paint);
}
invalidate();
}
break;
case MotionEvent.ACTION_UP:
// touch drop - just do things here after dropping
break;
}
// redraw the canvas
invalidate();
return true;
}
public void shade_region_between_points() {
canvas.drawRect(point1.x, point3.y, point3.x, point1.y, paint);
}
}
Следующий класс используется для хранения объектов
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Point;
public class ColorBall {
Bitmap bitmap;
Context mContext;
Point point;
int id;
static int count = 0;
public ColorBall(Context context, int resourceId, Point point) {
this.id = count++;
bitmap = BitmapFactory.decodeResource(context.getResources(),
resourceId);
mContext = context;
this.point = point;
}
public int getWidthOfBall() {
return bitmap.getWidth();
}
public int getHeightOfBall() {
return bitmap.getHeight();
}
public Bitmap getBitmap() {
return bitmap;
}
public int getX() {
return point.x;
}
public int getY() {
return point.y;
}
public int getID() {
return id;
}
public void setX(int x) {
point.x = x;
}
public void setY(int y) {
point.y = y;
}
}
Рабочая демонстрация https://www.youtube.com/watch?v=BfYd7Xa-tCc
Я не был доволен самыми высокими оценками ответов по нескольким причинам.
1) их было нелегко использовать в качестве представления в xml- атрибуты отсутствуют, поэтому представление не может быть легко переработано.
2) глупо было делать растровые изображения, когда проще было вставить в xml отрисовку
3) они не учитывают границы вида
4) они не предотвращают инверсию прямоугольника, перетаскивая слишком далеко влево или вверх
5) они не учитывают смещение от позиции касания к центру угловых точек
6) они оба зависят от устаревшего метода растрового изображения
7) и самое главное, я не мог заставить кого-либо из них работать
Я допускаю, что мое решение специализировано для квадратного вида, но его можно довольно легко настроить, чтобы иметь минимальную сторону X и минимальную сторону Y.
Поместите это в папку res/values:
custom_attributes.xml
<?xml version="1.0" encoding="utf-8"?>
<resources>
<declare-styleable name="IconCropView">
<attr name="minimumSide" format="dimension"/>
<attr name="resizeCornerDrawable" format="reference"/>
<attr name="moveCornerDrawable" format="reference"/>
<attr name="cornerColor" format="color"/>
<attr name="edgeColor" format="color" />
<attr name="outsideCropColor" format="color" />
<attr name="cornerSize" format="dimension" />
</declare-styleable>
</resources>
Добавьте это в Java-пакет IconCropView.java
package your_package;
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.drawable.Drawable;
import android.support.annotation.Nullable;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import your_package.R;
public class IconCropView extends View {
//contants strings
private static final String TAG = "IconCropView";
//drawing objects
private Paint paint;
//point objects
private Point[] points;
private Point start;
private Point offset;
//variable ints
private int minimumSideLength;
private int side;
private int halfCorner;
private int cornerColor;
private int edgeColor;
private int outsideColor;
private int corner = 5;
//variable booleans
private boolean initialized = false;
//drawables
private Drawable moveDrawable;
private Drawable resizeDrawable1, resizeDrawable2, resizeDrawable3;
//context
Context context;
public IconCropView(Context context) {
super(context);
this.context = context;
init(null);
}
public IconCropView(Context context, @Nullable AttributeSet attrs) {
super(context, attrs);
this.context = context;
init(attrs);
}
public IconCropView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
this.context = context;
init(attrs);
}
public IconCropView(Context context, @Nullable AttributeSet attrs, int defStyleAttr, int defStyleRes) {
super(context, attrs, defStyleAttr, defStyleRes);
this.context = context;
init(attrs);
}
private void init(@Nullable AttributeSet attrs){
paint = new Paint();
start = new Point();
offset = new Point();
TypedArray ta = context.getTheme().obtainStyledAttributes(attrs, R.styleable.IconCropView, 0, 0);
//initial dimensions
minimumSideLength = ta.getDimensionPixelSize(R.styleable.IconCropView_minimumSide, 20);
side = minimumSideLength;
halfCorner = (ta.getDimensionPixelSize(R.styleable.IconCropView_cornerSize, 20))/2;
//colors
cornerColor = ta.getColor(R.styleable.IconCropView_cornerColor, Color.BLACK);
edgeColor = ta.getColor(R.styleable.IconCropView_edgeColor, Color.WHITE);
outsideColor = ta.getColor(R.styleable.IconCropView_outsideCropColor, Color.parseColor("#00000088"));
//initialize corners;
points = new Point[4];
points[0] = new Point();
points[1] = new Point();
points[2] = new Point();
points[3] = new Point();
//init corner locations;
//top left
points[0].x = 0;
points[0].y = 0;
//top right
points[1].x = minimumSideLength;
points[1].y = 0;
//bottom left
points[2].x = 0;
points[2].y = minimumSideLength;
//bottom right
points[3].x = minimumSideLength;
points[3].y = minimumSideLength;
//init drawables
moveDrawable = ta.getDrawable(R.styleable.IconCropView_moveCornerDrawable);
resizeDrawable1 = ta.getDrawable(R.styleable.IconCropView_resizeCornerDrawable);
resizeDrawable2 = ta.getDrawable(R.styleable.IconCropView_resizeCornerDrawable);
resizeDrawable3 = ta.getDrawable(R.styleable.IconCropView_resizeCornerDrawable);
//set drawable colors
moveDrawable.setTint(cornerColor);
resizeDrawable1.setTint(cornerColor);
resizeDrawable2.setTint(cornerColor);
resizeDrawable3.setTint(cornerColor);
//recycle attributes
ta.recycle();
//set initialized to true
initialized = true;
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
//set paint to draw edge, stroke
if(initialized) {
paint.setAntiAlias(true);
paint.setStyle(Paint.Style.STROKE);
paint.setStrokeJoin(Paint.Join.ROUND);
paint.setColor(edgeColor);
paint.setStrokeWidth(4);
//crop rectangle
canvas.drawRect(points[0].x + halfCorner,points[0].y + halfCorner, points[0].x + halfCorner + side, points[0].y + halfCorner + side, paint);
//set paint to draw outside color, fill
paint.setStyle(Paint.Style.FILL);
paint.setColor(outsideColor);
//top rectangle
canvas.drawRect(0, 0, canvas.getWidth(), points[0].y + halfCorner, paint);
//left rectangle
canvas.drawRect(0, points[0].y + halfCorner, points[0].x + halfCorner, canvas.getHeight(), paint);
//right rectangle
canvas.drawRect(points[0].x + halfCorner + side, points[0].y + halfCorner, canvas.getWidth(), points[0].y + halfCorner + side, paint);
//bottom rectangle
canvas.drawRect(points[0].x + halfCorner, points[0].y + halfCorner + side, canvas.getWidth(), canvas.getHeight(), paint);
//set bounds of drawables
moveDrawable.setBounds(points[0].x, points[0].y, points[0].x + halfCorner*2, points[0].y + halfCorner*2);
resizeDrawable1.setBounds(points[1].x, points[1].y, points[1].x + halfCorner*2, points[1].y + halfCorner*2);
resizeDrawable2.setBounds(points[2].x, points[2].y, points[2].x + halfCorner*2, points[2].y + halfCorner*2);
resizeDrawable3.setBounds(points[3].x, points[3].y, points[3].x + halfCorner*2, points[3].y+ halfCorner*2);
//place corner drawables
moveDrawable.draw(canvas);
resizeDrawable1.draw(canvas);
resizeDrawable2.draw(canvas);
resizeDrawable3.draw(canvas);
}
}
@Override
public boolean onTouchEvent(MotionEvent event) {
//return super.onTouchEvent(event);
switch(event.getActionMasked()){
case MotionEvent.ACTION_DOWN:{
//get the coordinates
start.x = (int)event.getX();
start.y = (int)event.getY();
//get the corner touched if any
corner = getCorner(start.x, start.y);
//get the offset of touch(x,y) from corner top-left point
offset = getOffset(start.x, start.y, corner);
//account for touch offset in starting point
start.x = start.x - offset.x;
start.y = start.y - offset.y;
break;
}
case MotionEvent.ACTION_UP:{
}
case MotionEvent.ACTION_MOVE:{
if(corner == 0) {
points[0].x = Math.max(points[0].x + (int) Math.min(Math.floor((event.getX() - start.x - offset.x)), Math.floor(getWidth() - points[0].x - 2*halfCorner - side)), 0);
points[1].x = Math.max(points[1].x + (int) Math.min(Math.floor((event.getX() - start.x - offset.x)), Math.floor(getWidth() - points[1].x - 2*halfCorner)), side);
points[2].x = Math.max(points[2].x + (int) Math.min(Math.floor((event.getX() - start.x - offset.x)), Math.floor(getWidth() - points[2].x - 2*halfCorner - side)), 0);
points[3].x = Math.max(points[3].x + (int) Math.min(Math.floor((event.getX() - start.x - offset.x)), Math.floor(getWidth() - points[3].x - 2*halfCorner)), side);
points[0].y = Math.max(points[0].y + (int) Math.min(Math.floor((event.getY() - start.y - offset.y)), Math.floor(getHeight() - points[0].y - 2*halfCorner - side)), 0);
points[1].y = Math.max(points[1].y + (int) Math.min(Math.floor((event.getY() - start.y - offset.y)), Math.floor(getHeight() - points[1].y - 2*halfCorner - side)), 0);
points[2].y = Math.max(points[2].y + (int) Math.min(Math.floor((event.getY() - start.y - offset.y)), Math.floor(getHeight() - points[2].y - 2*halfCorner)), side);
points[3].y = Math.max(points[3].y + (int) Math.min(Math.floor((event.getY() - start.y - offset.y)), Math.floor(getHeight() - points[3].y - 2*halfCorner)), side);
start.x = points[0].x;
start.y = points[0].y;
invalidate();
}else if (corner == 1){
side = Math.min((Math.min((Math.max(minimumSideLength, (int)(side + Math.floor(event.getX()) - start.x - offset.x))), side + (getWidth() - points[1].x - 2* halfCorner ))),side + (getHeight() - points[2].y - 2* halfCorner ));
points[1].x = points[0].x + side;
points[3].x = points[0].x + side;
points[3].y = points[0].y + side;
points[2].y = points[0].y + side;
start.x = points[1].x;
invalidate();
}else if (corner == 2){
side = Math.min((Math.min((Math.max(minimumSideLength, (int)(side + Math.floor(event.getY()) - start.y - offset.y))), side + (getHeight() - points[2].y - 2* halfCorner ))),side + (getWidth() - points[1].x - 2* halfCorner ));
points[2].y = points[0].y + side;
points[3].y = points[0].y + side;
points[3].x = points[0].x + side;
points[1].x = points[0].x + side;
start.y = points[2].y;
invalidate();
}else if (corner == 3){
side = Math.min((Math.min((Math.min((Math.max(minimumSideLength, (int)(side + Math.floor(event.getX()) - start.x - offset.x))), side + (getWidth() - points[3].x - 2* halfCorner ))),side + (getHeight() - points[3].y - 2* halfCorner ))), Math.min((Math.min((Math.max(minimumSideLength, (int)(side + Math.floor(event.getY()) - start.y - offset.y))), side + (getHeight() - points[3].y - 2* halfCorner ))),side + (getWidth() - points[3].x - 2* halfCorner )));
points[1].x = points[0].x + side;
points[3].x = points[0].x + side;
points[3].y = points[0].y + side;
points[2].y = points[0].y + side;
start.x = points[3].x;
points[2].y = points[0].y + side;
points[3].y = points[0].y + side;
points[3].x = points[0].x + side;
points[1].x = points[0].x + side;
start.y = points[3].y;
invalidate();
}
break;
}
}
return true;
}
private int getCorner(float x, float y){
int corner = 5;
for (int i = 0; i < points.length; i++){
float dx = x - points[i].x;
float dy = y - points[i].y;
int max = halfCorner * 2;
if(dx <= max && dx >= 0 && dy <= max && dy >= 0){
return i;
}
}
return corner;
}
private Point getOffset(int left, int top, int corner){
Point offset = new Point();
if(corner == 5){
offset.x = 0;
offset.y = 0;
}else{
offset.x = left - points[corner].x;
offset.y = top - points[corner].y;
}
return offset;
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
}
В вашем макете xml:
1) Вы должны указать угол рисования
2) Для углов изменения размера необходимо указать чертеж
3) размер угла по умолчанию составляет 20 пикселей
4) минимальная сторона должна быть не меньше углового размера - значение по умолчанию составляет 20 пикселей
5) Вы должны включить пространство имен " http://schemas.android.com/apk/res-auto " в свое корневое представление (я использовал псевдоним xlmn:app="http://schemas.android.com/apk/ Рез-авто ")
пример макета XML
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:background="@color/primary"
android:layout_width="match_parent"
android:layout_height="match_parent">
<ImageView
android:id="@+id/crop_image"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginStart="10dp"
android:layout_marginTop="10dp"
android:layout_marginEnd="10dp"
android:layout_marginBottom="10dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="1.0"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.0"
app:srcCompat="@mipmap/ic_launcher" />
<your_package.IconCropView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@color/transparent"
app:minimumSide="60dp"
app:resizeCornerDrawable="@drawable/adjust_edge_circle"
app:moveCornerDrawable="@drawable/move_box_circle"
app:cornerColor="@color/turq"
app:edgeColor="@color/colorPrimary"
app:outsideCropColor="@color/transparent_50"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:cornerSize="20dp"/>
Отредактированный ответ Нгуен Минь Бинь работал на меня. Но мне нужно было добавить исправление, чтобы не допустить попадания идентификатора шара. Это произошло для меня, если мне пришлось заново открыть действие, в котором размещался пользовательский вид. Я исправил эти строки:
this.id = count ++;
чтобы:
if (count > 3) count = 0;
this.id = count++;
Следующий код представляет собой версию C# (в настоящее время я занимаюсь разработкой приложения для MonoDroid/Xamarin) запрошенного кода, но с некоторыми улучшениями и возможностью перетаскивания прямоугольника. Еще хочу добавить некоторые функции, отредактирую позже.
namespace ImagePlayground
{
[Activity (Label = "MyView2")]
public class MyView2 : View
{
Graphics.Point[] points = new Graphics.Point[4];
// Array that hold the circle
private List<ResizeCircle> circles = new List<ResizeCircle>();
// Variable to keep tracking of which circle is being dragged
private int circleId = -1;
// Points are grouped in groups of two so there's always only one fixed point
// groupId = 0 > Touch Inside the Rectangle
// groupId = 1 > Points 0 and 2
// groupId = 2 > Points 1 and 3
int groupId = -1;
// FirstTouch's Coordinate for Tracking on Dragging
int xFirstTouch = 0;
int yFirstTouch = 0;
/** Main Bitmap **/
private Bitmap mBitmap = null;
/** Measured Size of the View **/
private Rect mMeasuredRect;
/** Paint to Draw Rectangles **/
private Paint mRectPaint;
public MyView2(Context ctx) : base (ctx){
init (ctx);
}
public MyView2 (Context ctx, IAttributeSet attrs) : base (ctx, attrs){
init (ctx);
}
public MyView2 (Context ctx, IAttributeSet attrs, int defStyle) : base(ctx,attrs,defStyle){
init (ctx);
}
private void init(Context ctx){
// For Touch Events
Focusable = true;
// Draw the Image on the Background
mBitmap = BitmapFactory.DecodeResource(ctx.Resources, Resource.Drawable.bg);
// Sets up the paint for the Drawable Rectangles
mRectPaint = new Paint ();
mRectPaint.Color = Android.Graphics.Color.Aqua;
mRectPaint.StrokeWidth = 4;
mRectPaint.SetStyle (Paint.Style.Stroke);
}
protected override void OnDraw(Canvas canvas){
// Background Bitmap to Cover all Area
canvas.DrawBitmap(mBitmap, null, mMeasuredRect, null);
// Just draw the points only if it has already been initiated
if (points [3] != null) {
int left, top, right, bottom;
left = points [0].X;
top = points [0].Y;
right = points [0].X;
bottom = points [0].Y;
// Sets the circles' locations
for (int i = 1; i < points.Length; i++) {
left = left > points [i].X ? points [i].X : left;
top = top > points [i].Y ? points [i].Y : top;
right = right < points [i].X ? points [i].X : right;
bottom = bottom < points [i].Y ? points [i].Y : bottom;
}
mRectPaint.AntiAlias = true;
mRectPaint.Dither = true;
mRectPaint.StrokeJoin = Paint.Join.Round;
mRectPaint.StrokeWidth = 5;
mRectPaint.SetStyle (Paint.Style.Stroke);
mRectPaint.Color = Graphics.Color.ParseColor ("#0079A3");
canvas.DrawRect (
left + circles [0].GetCircleWidth () / 2,
top + circles [0].GetCircleWidth () / 2,
right + circles [2].GetCircleWidth () / 2,
bottom + circles [2].GetCircleWidth () / 2, mRectPaint);
// Fill The Rectangle
mRectPaint.SetStyle (Paint.Style.Fill);
mRectPaint.Color = Graphics.Color.ParseColor ("#B2D6E3");
mRectPaint.Alpha = 75;
mRectPaint.StrokeWidth = 0;
canvas.DrawRect (
left + circles [0].GetCircleWidth () / 2,
top + circles [0].GetCircleWidth () / 2,
right + circles [2].GetCircleWidth () / 2,
bottom + circles [2].GetCircleWidth () / 2, mRectPaint);
// DEBUG
mRectPaint.Color = Graphics.Color.Red;
mRectPaint.TextSize = 18;
mRectPaint.StrokeWidth = 0;
// Draw every circle on the right position
for (int i = 0; i < circles.Count (); i++) {
ResizeCircle circle = circles [i];
float x = circle.GetX ();
float y = circle.GetY ();
canvas.DrawBitmap (circle.GetBitmap (), x, y,
mRectPaint);
// DEBUG
// canvas.DrawText ("" + (i + 1), circle.GetX (), circle.GetY (), mRectPaint);
}
}
}
public override bool OnTouchEvent(MotionEvent e){
// Get the Coordinates of Touch
int xTouch = (int) e.GetX ();
int yTouch = (int) e.GetY ();
int actionIndex = e.ActionIndex;
switch (e.ActionMasked) {
// In case user touch the screen
case MotionEventActions.Down:
// If no points were created
if (points [0] == null) {
// Offset to create the points
int offset = 60;
// Initialize a new Rectangle.
points [0] = new Graphics.Point ();
points [0].X = xTouch;
points [0].Y = yTouch;
points [1] = new Graphics.Point ();
points [1].X = xTouch;
points [1].Y = yTouch + offset;
points [2] = new Graphics.Point ();
points [2].X = xTouch + offset;
points [2].Y = yTouch + offset;
points [3] = new Graphics.Point ();
points [3].X = xTouch + offset;
points [3].Y = yTouch;
// Add each circle to circles array
foreach (Graphics.Point pt in points) {
circles.Add (new ResizeCircle (Context, Resource.Drawable.circle, pt));
}
} else {
// Register Which Circle (if any) th user has touched
groupId = getTouchedCircle (xTouch, yTouch);
xFirstTouch = xTouch;
yFirstTouch = yTouch;
}
break;
case MotionEventActions.PointerDown:
break;
case MotionEventActions.Move:
if (groupId == 1 || groupId == 2) {
// Move touched Circle as the finger moves
circles[circleId].SetX(xTouch);
circles[circleId].SetY(yTouch);
// Move the two other circles accordingly
if (groupId == 1) {
circles[1].SetX(circles[0].GetX());
circles[1].SetY(circles[2].GetY());
circles[3].SetX(circles[2].GetX());
circles[3].SetY(circles[0].GetY());
} else {
circles[0].SetX(circles[1].GetX());
circles[0].SetY(circles[3].GetY());
circles[2].SetX(circles[3].GetX());
circles[2].SetY(circles[1].GetY());
}
Invalidate();
} else if (groupId == 0){
// Calculate the delta for the dragging
int xDelta = (xTouch-xFirstTouch);
int yDelta = (yTouch-yFirstTouch);
xFirstTouch = xTouch;
yFirstTouch = yTouch;
// Move each circle accordingly
foreach (ResizeCircle circle in circles) {
circle.SetX (circle.GetX () + xDelta);
circle.SetY (circle.GetY () + yDelta);
}
// Redraw the view
Invalidate ();
}
break;
case MotionEventActions.Up:
break;
default:
break;
}
Invalidate ();
return true;
}
private int getTouchedCircle(int xTouch, int yTouch){
int groupId = -1;
for (int i = 0; i < circles.Count; i++) {
ResizeCircle circle = circles [i];
// Check if the touch was inside the bounds of the circle
int centerX = circle.GetX () + circle.GetCircleWidth ();
int centerY = circle.GetY () + circle.GetCircleHeight ();
// Calculate the radius from the touch to the center of the circle
double radCircle = Math.Sqrt ((double)(((centerX - xTouch) * (centerX - xTouch)) + (centerY - yTouch)
* (centerY - yTouch)));
// If the touch was on one of the circles
if (radCircle < circle.GetCircleWidth ()) {
circleId = circle.GetID ();
if (circleId == 1 || circleId == 3) {
groupId = 2;
break;
} else {
groupId = 1;
break;
}
} else {
// User didn't touch any of the circles nor the inside area
groupId = -1;
}
}
// If the touch wasn't on one of the circles, check if it was inside the rectangle
if (groupId == -1) {
List<int> xCoords = new List<int> ();
List<int> yCoords = new List<int> ();
// Gather Coordinates from all circles
foreach (ResizeCircle circle in circles){
xCoords.Add (circle.GetX());
yCoords.Add (circle.GetY());
}
// Store the max and min coordinates
int minX = xCoords.Min ();
int maxX = xCoords.Max ();
int minY = yCoords.Min ();
int maxY = yCoords.Max ();
// Check if user has touched inside the rectangle
if ((xTouch > minX && xTouch < maxX) && (yTouch > minY && yTouch < maxY)) {
// User has touched inside the Rectangle
groupId = 0;
}
}
return groupId;
}
protected override void OnMeasure(int widthMeasureSpec, int heightMeasureSpec){
base.OnMeasure (widthMeasureSpec, heightMeasureSpec);
mMeasuredRect = new Rect (0, 0, MeasuredWidth, MeasuredHeight);
}
public class ResizeCircle {
Bitmap bitmap;
Graphics.Point point;
int id;
static int count = 0;
public ResizeCircle(Context context, int resourceId, Graphics.Point point) {
this.id = count++;
bitmap = BitmapFactory.DecodeResource(context.Resources,
resourceId);
Log.Debug("BITMAP" , bitmap.Height.ToString());
this.point = point;
}
public int GetCircleWidth() {
return bitmap.Width;
}
public int GetCircleHeight() {
return bitmap.Height;
}
public Bitmap GetBitmap() {
return bitmap;
}
public int GetX() {
return point.X;
}
public int GetY() {
return point.Y;
}
public int GetID() {
return id;
}
public void SetX(int x) {
point.X = x;
}
public void SetY(int y) {
point.Y = y;
}
}
}
}