修复View初始黑屏的Bug

Author: JinJieGu

app/src/main/java/jaygoo/wavelineview/LeakTestActivity.java

@@ -52,7 +52,7 @@ public void onClick(View v) {
     @Override
     protected void onResume() {
         super.onResume();
-        waveLineView.onResume(true);
+        waveLineView.onResume();
     }
 
     @Override

app/src/main/java/jaygoo/wavelineview/MainActivity.java

@@ -42,11 +42,19 @@ public void onClick(View v) {
         });
     }
 
+    @Override
+    public void onWindowFocusChanged(boolean hasFocus) {
+        super.onWindowFocusChanged(hasFocus);
+        if (hasFocus){
+//            waveLineView.justDrawBackground();
+        }
+    }
 
     @Override
     protected void onResume() {
         super.onResume();
-        waveLineView.onResume(true);
+        waveLineView.onResume();
+
     }
 
     @Override

library/src/main/java/jaygoo/widget/wlv/RenderView.java

@@ -18,7 +18,22 @@
  */
 public abstract class RenderView extends SurfaceView implements SurfaceHolder.Callback {
 
-    private boolean isAutoStartAnim = false;
+    //是否正在绘制动画
+    private boolean isStartAnim = false;
+    private final static Object surfaceLock = new Object();
+    private RenderThread renderThread;
+    /**
+     * 绘制背景，防止开始时黑屏
+     * 子View可以执行此方法
+     * @param canvas
+     */
+    protected abstract void doDrawBackground(Canvas canvas);
+    /**
+     * 渲染surfaceView的回调方法。
+     *
+     * @param canvas 画布
+     */
+    protected abstract void onRender(Canvas canvas, long millisPassed);
 
     public RenderView(Context context) {
         this(context, null);
@@ -77,19 +92,22 @@ public void run() {
                         if (getSurfaceHolder() != null && getRenderView() != null) {
                             Canvas canvas = getSurfaceHolder().lockCanvas();
                             if (canvas != null) {
-                                getRenderView().render(canvas, System.currentTimeMillis() - startAt);  //这里做真正绘制的事情
+                                getRenderView().doDrawBackground(canvas);
+                                if (getRenderView().isStartAnim) {
+                                    getRenderView().render(canvas, System.currentTimeMillis() - startAt);  //这里做真正绘制的事情
+                                }
                                 getSurfaceHolder().unlockCanvasAndPost(canvas);
                             }
                         }else {
                             running = false;
                         }
-                        try {
-                            Thread.sleep(SLEEP_TIME);
-                        } catch (InterruptedException e) {
-                            e.printStackTrace();
-                        }
-                    }
 
+                    }
+                    try {
+                        Thread.sleep(SLEEP_TIME);
+                    } catch (InterruptedException e) {
+                        e.printStackTrace();
+                    }
                 }
 
             }
@@ -103,8 +121,7 @@ public void setRun(boolean isRun) {
 
     }
 
-    private final static Object surfaceLock = new Object();
-    private RenderThread renderThread;
+
 
     @Override
     public void surfaceCreated(SurfaceHolder holder) {
@@ -130,20 +147,6 @@ public void onResume(){
     }
 
 
-    /**
-     * 解锁暂停，继续执行绘制任务
-     * @param isAutoStartAnim 是否当Resume时自动启动动画
-     */
-    public void onResume(boolean isAutoStartAnim){
-        synchronized (surfaceLock){
-            this.isAutoStartAnim = isAutoStartAnim;
-            if (renderThread != null) {
-                renderThread.isPause = false;
-                surfaceLock.notifyAll();
-            }
-        }
-    }
-
     //假暂停，并没有结束Thread
     public void onPause(){
         synchronized (surfaceLock){
@@ -168,12 +171,14 @@ public void surfaceDestroyed(SurfaceHolder holder) {
     }
 
     public void onWindowFocusChanged(boolean hasFocus) {
-        if (hasFocus && isAutoStartAnim){
+        if (hasFocus && isStartAnim){
             startAnim();
+        }else {
+            startThread();
         }
     }
-    /*绘图*/
 
+    /*绘图*/
     public interface IRenderer {
         void onRender(Canvas canvas, long millisPassed);
     }
@@ -194,15 +199,12 @@ private void render(Canvas canvas, long millisPassed) {
         }
     }
 
-    /**
-     * 渲染surfaceView的回调方法。
-     *
-     * @param canvas 画布
-     */
-    protected void onRender(Canvas canvas, long millisPassed) {
+    public void startAnim(){
+        isStartAnim = true;
+        startThread();
     }
 
-    public void startAnim(){
+    private void startThread(){
 
         if (renderThread != null && !renderThread.running) {
             renderThread.setRun(true);
@@ -219,6 +221,7 @@ public void startAnim(){
     }
 
     public void stopAnim(){
+        isStartAnim = false;
         if (renderThread != null && renderThread.running) {
             renderThread.setRun(false);
             renderThread.interrupt();

library/src/main/java/jaygoo/widget/wlv/WaveLineView.java

@@ -124,17 +124,20 @@ private void initAttr(AttributeSet attrs) {
         checkSensibilityValue();
     }
 
+    @Override
+    protected void doDrawBackground(Canvas canvas) {
+        //绘制背景
+        canvas.drawColor(backGroundColor);
+    }
+
     @Override
     protected void onRender(Canvas canvas, long millisPassed) {
-        super.onRender(canvas, millisPassed);
         float offset = millisPassed / offsetSpeed;
 
         if (null == samplingX){
             initDraw(canvas);
         }
 
-        //绘制背景
-        canvas.drawColor(backGroundColor);
         if (lineAnim(canvas)) {
             resetPaths();
             softerChangeVolume();
@@ -276,7 +279,7 @@ public void startAnim() {
     @Override
     public void stopAnim() {
         super.stopAnim();
-//        clearDraw();
+        clearDraw();
     }
 
     //清空画布所有内容