Java 如何在应用程序中以片段形式保存用户绘图?
我正在创建一个应用程序,其中多个片段有一个视频和一个自定义绘图视图(让我们称之为画布),用户可以用手指画一条线。我想弄清楚的是:在用户在画布上绘制之后,如果用户转到其他片段或离开应用程序,我如何让应用程序保留该绘图 编辑Java 如何在应用程序中以片段形式保存用户绘图?,java,android,android-studio,Java,Android,Android Studio,我正在创建一个应用程序,其中多个片段有一个视频和一个自定义绘图视图(让我们称之为画布),用户可以用手指画一条线。我想弄清楚的是:在用户在画布上绘制之后,如果用户转到其他片段或离开应用程序,我如何让应用程序保留该绘图 编辑 与前面相同动作的片段,来自我的测试应用程序 编辑 现在使用getter控制绘图事件的片段 导入android.content.Context; 导入android.graphics.Bitmap; 导入android.graphics.BlurMaskFilter; 导入and
与前面相同动作的片段,来自我的测试应用程序 编辑 现在使用getter控制绘图事件的片段
导入android.content.Context;
导入android.graphics.Bitmap;
导入android.graphics.BlurMaskFilter;
导入android.graphics.Canvas;
导入android.graphics.Color;
导入android.graphics.maskfilter;
导入android.graphics.MaskFilter;
导入android.graphics.Paint;
导入android.graphics.Path;
导入android.util.AttributeSet;
导入android.util.DisplayMetrics;
导入android.view.MotionEvent;
导入android.view.view;
导入java.util.ArrayList;
公共类PaintView扩展了视图{
公共静态int笔刷大小=10;
公共静态最终int默认值_COLOR=COLOR.WHITE;
公共静态int DEFAULT\u BG\u COLOR=COLOR.GRAY;
专用静态最终浮动接触公差=4;
私人浮动mX,我的;
专用路径mPath;
私人油漆;
私有ArrayList路径=新ArrayList();
私人色彩;
private int backgroundColor=默认背景颜色;
私有内冲程宽度;
私有布尔浮雕;
私有布尔模糊;
私人MaskFilter mEmboss;
私人MaskFilter mBlur;
私有位图mBitmap;
私人帆布mCanvas;
专用油漆mBitmapPaint=新油漆(油漆抖动标志);
公共PaintView(上下文){
这个(上下文,空);
}
公共画图视图(上下文、属性集属性){
超级(上下文,attrs);
mPaint=新油漆();
mPaint.setAntiAlias(true);
mPaint.setDither(true);
mPaint.setColor(默认颜色);
mPaint.setStyle(油漆、样式、笔划);
mPaint.setStrokeJoin(油漆.连接.圆形);
mPaint.setStrokeCap(油漆盖圆形);
mPaint.setXfermode(null);
mPaint.setAlpha(0xff);
mEmboss=新的浮雕maskfilter(新的float[]{1,1,1},0.4f,6,3.5f);
mBlur=新的模糊过滤器(5,BlurMaskFilter.Blur.NORMAL);
}
//有问题的人
公共ArrayList getpath(){
返回路径;
}
公共void init(DisplayMetrics){
int height=metrics.heightPixels;
int width=metrics.widthPixels;
mBitmap=Bitmap.createBitmap(宽度、高度、Bitmap.Config.ARGB_8888);
mCanvas=新画布(mBitmap);
currentColor=默认颜色;
笔划宽度=画笔大小;
}
公共无效正常值(){
浮雕=假;
模糊=错误;
}
公共空间清除(){
backgroundColor=默认的背景颜色;
清除路径();
正常();
使无效();
}
@凌驾
受保护的void onDraw(画布){
canvas.save();
mCanvas.drawColor(背景色);
对于(FingerPath fp:路径){
mPaint.setColor(fp.color);
mPaint.设置行程宽度(fp.行程宽度);
mPaint.setMaskFilter(null);
if(fp.浮雕)
mPaint.setMaskFilter(mEmboss);
else if(fp.blur)
mPaint.setMaskFilter(mBlur);
mCanvas.drawPath(fp.path,mPaint);
}
drawBitmap(mBitmap,0,0,mbitMapPoint);
canvas.restore();
}
专用void touchStart(浮点x、浮点y){
mPath=新路径();
FingerPath fp=新的FingerPath(当前颜色、浮雕、模糊、笔划宽度、,
mPath);
添加路径(fp);
mPath.reset();
移动到(x,y)的速度;
mX=x;
mY=y;
}
私有无效触摸移动(浮动x、浮动y){
float dx=数学绝对值(x-mX);
float dy=Math.abs(y-mY);
如果(dx>=接触公差| | dy>=接触公差){
兆帕四分之一秒(mX,mY,(x+mX)/2,(y+mY)/2);
mX=x;
mY=y;
}
}
私人修补{
mPath.lineTo(mX,mY);
}
@凌驾
公共布尔onTouchEvent(运动事件){
float x=event.getX();
float y=event.getY();
开关(event.getAction()){
case MotionEvent.ACTION\u DOWN:
touchStart(x,y);
使无效();
打破
case MotionEvent.ACTION\u移动:
touchMove(x,y);
使无效();
打破
case MotionEvent.ACTION\u UP:
修补();
使无效();
打破
}
返回true;
}
}
新更改的FingerPath类
import android.graphics.Path;
import android.os.Parcel;
import android.os.Parcelable;
import java.util.ArrayList;
public class FingerPath implements Parcelable {
public int color;
public boolean emboss;
public boolean blur;
public int strokeWidth;
public Path path;
public FingerPath(int color, boolean emboss, boolean blur, int strokeWidth,
Path path) {
this.color = color;
this.emboss = emboss;
this.blur = blur;
this.strokeWidth = strokeWidth;
this.path = path;
}
protected FingerPath(Parcel in) {
color = in.readInt();
emboss = in.readByte() != 0;
blur = in.readByte() != 0;
strokeWidth = in.readInt();
}
public static final Creator<FingerPath> CREATOR = new Creator<FingerPath>() {
@Override
public FingerPath createFromParcel(Parcel in) {
return new FingerPath(in);
}
@Override
public FingerPath[] newArray(int size) {
return new FingerPath[size];
}
};
@Override
public int describeContents() {
return 0;
}
@Override
public void writeToParcel(Parcel parcel, int i) {
parcel.writeInt(color);
parcel.writeByte((byte) (emboss ? 1 : 0));
parcel.writeByte((byte) (blur ? 1 : 0));
parcel.writeInt(strokeWidth);
}
导入android.graphics.Path;
导入android.os.packet;
导入android.os.Parcelable;
导入java.util.ArrayList;
公共类FingerPath实现了Parcelable{
公共int颜色;
公共布尔浮雕;
公共布尔模糊;
公共内冲程宽度;
公共路径;
公共FingerPath(整数颜色、布尔浮雕、布尔模糊、整数笔划宽度、,
路径(路径){
这个颜色=颜色;
this.emboss=浮雕;
this.blur=模糊;
this.strokeWidth=strokeWidth;
this.path=path;
}
受保护的指路(地块在中){
color=in.readInt();
浮雕=in.readByte()!=0;
blur=in.readByte()!=0;
strokeWidth=in.readInt();
}
公共静态最终创建者=新创建者(){
@凌驾
公共FingerPath createFromParcel(地块中){
返回新的FingerPath(在中);
}
@凌驾
公共FingerPath[]新数组(整数大小){
返回新的FingerPath[大小];
}
};
@凌驾
公共int描述内容(){
返回0;
}
@凌驾
公共无效书面包裹(包裹,内部i){
包裹书写(颜色);
parcel.writeByte((字节)(浮雕?1:0));
parcel.writeByte((字节)(模糊?1:0));
包裹写入(笔划宽度);
}
简单的方法是查看
,并在还原片段时将该图像设置为背景
但您可能希望继续编辑已绘制的路径选项,因此必须将所有的FingerPath
s存储在onSaveInstanceState
方法中,并
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BlurMaskFilter;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.EmbossMaskFilter;
import android.graphics.MaskFilter;
import android.graphics.Paint;
import android.graphics.Path;
import android.util.AttributeSet;
import android.util.DisplayMetrics;
import android.view.MotionEvent;
import android.view.View;
import java.util.ArrayList;
public class PaintView extends View {
public static int BRUSH_SIZE = 10;
public static final int DEFAULT_COLOR = Color.WHITE;
public static int DEFAULT_BG_COLOR = Color.GRAY;
private static final float TOUCH_TOLERANCE = 4;
private float mX, mY;
private Path mPath;
private Paint mPaint;
private ArrayList<FingerPath> paths = new ArrayList<>();
private int currentColor;
private int backgroundColor = DEFAULT_BG_COLOR;
private int strokeWidth;
private boolean emboss;
private boolean blur;
private MaskFilter mEmboss;
private MaskFilter mBlur;
private Bitmap mBitmap;
private Canvas mCanvas;
private Paint mBitmapPaint = new Paint(Paint.DITHER_FLAG);
public PaintView(Context context) {
this(context, null);
}
public PaintView(Context context, AttributeSet attrs) {
super(context, attrs);
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setDither(true);
mPaint.setColor(DEFAULT_COLOR);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setXfermode(null);
mPaint.setAlpha(0xff);
mEmboss = new EmbossMaskFilter(new float[] {1, 1, 1}, 0.4f, 6, 3.5f);
mBlur = new BlurMaskFilter(5, BlurMaskFilter.Blur.NORMAL);
}
//the getter in question
public ArrayList getPaths() {
return paths;
}
public void init(DisplayMetrics metrics) {
int height = metrics.heightPixels;
int width = metrics.widthPixels;
mBitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
mCanvas = new Canvas(mBitmap);
currentColor = DEFAULT_COLOR;
strokeWidth = BRUSH_SIZE;
}
public void normal() {
emboss = false;
blur = false;
}
public void clear() {
backgroundColor = DEFAULT_BG_COLOR;
paths.clear();
normal();
invalidate();
}
@Override
protected void onDraw(Canvas canvas) {
canvas.save();
mCanvas.drawColor(backgroundColor);
for (FingerPath fp: paths) {
mPaint.setColor(fp.color);
mPaint.setStrokeWidth(fp.strokeWidth);
mPaint.setMaskFilter(null);
if (fp.emboss)
mPaint.setMaskFilter(mEmboss);
else if (fp.blur)
mPaint.setMaskFilter(mBlur);
mCanvas.drawPath(fp.path, mPaint);
}
canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);
canvas.restore();
}
private void touchStart(float x, float y) {
mPath = new Path();
FingerPath fp = new FingerPath(currentColor, emboss, blur, strokeWidth,
mPath);
paths.add(fp);
mPath.reset();
mPath.moveTo(x, y);
mX = x;
mY = y;
}
private void touchMove(float x, float y) {
float dx = Math.abs(x-mX);
float dy = Math.abs(y-mY);
if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE) {
mPath.quadTo(mX, mY, (x + mX) / 2, (y + mY) / 2);
mX = x;
mY = y;
}
}
private void touchUp() {
mPath.lineTo(mX, mY);
}
@Override
public boolean onTouchEvent(MotionEvent event) {
float x = event.getX();
float y = event.getY();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN :
touchStart(x, y);
invalidate();
break;
case MotionEvent.ACTION_MOVE :
touchMove(x, y);
invalidate();
break;
case MotionEvent.ACTION_UP :
touchUp();
invalidate();
break;
}
return true;
}
}
import android.graphics.Path;
import android.os.Parcel;
import android.os.Parcelable;
import java.util.ArrayList;
public class FingerPath implements Parcelable {
public int color;
public boolean emboss;
public boolean blur;
public int strokeWidth;
public Path path;
public FingerPath(int color, boolean emboss, boolean blur, int strokeWidth,
Path path) {
this.color = color;
this.emboss = emboss;
this.blur = blur;
this.strokeWidth = strokeWidth;
this.path = path;
}
protected FingerPath(Parcel in) {
color = in.readInt();
emboss = in.readByte() != 0;
blur = in.readByte() != 0;
strokeWidth = in.readInt();
}
public static final Creator<FingerPath> CREATOR = new Creator<FingerPath>() {
@Override
public FingerPath createFromParcel(Parcel in) {
return new FingerPath(in);
}
@Override
public FingerPath[] newArray(int size) {
return new FingerPath[size];
}
};
@Override
public int describeContents() {
return 0;
}
@Override
public void writeToParcel(Parcel parcel, int i) {
parcel.writeInt(color);
parcel.writeByte((byte) (emboss ? 1 : 0));
parcel.writeByte((byte) (blur ? 1 : 0));
parcel.writeInt(strokeWidth);
}