From 338192ad17bf9639ec74783e4a4d19f9037a915a Mon Sep 17 00:00:00 2001
From: hyb1996 <946994919@qq.com>
Date: Wed, 6 Dec 2017 20:30:06 +0800
Subject: [PATCH] fix: captureScreen() return null

---
 .../autojs/core/image/ScreenCapturer.java         | 15 ++++++++++-----
 .../com/stardust/autojs/runtime/api/Images.java   |  2 +-
 2 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/autojs/src/main/java/com/stardust/autojs/core/image/ScreenCapturer.java b/autojs/src/main/java/com/stardust/autojs/core/image/ScreenCapturer.java
index 95671c46..9f4bb6c7 100644
--- a/autojs/src/main/java/com/stardust/autojs/core/image/ScreenCapturer.java
+++ b/autojs/src/main/java/com/stardust/autojs/core/image/ScreenCapturer.java
@@ -34,6 +34,7 @@ public class ScreenCapturer {
     private volatile Looper mImageAcquireLooper;
     private volatile Image mUnderUsingImage;
     private volatile Image mCachedImage;
+    private volatile boolean mImageAvailable = false;
     private final int mScreenWidth;
     private final int mScreenHeight;
     private final int mScreenDensity;
@@ -90,6 +91,7 @@ public class ScreenCapturer {
                         mCachedImage.close();
                     }
                     mCachedImage = reader.acquireLatestImage();
+                    mImageAvailable = true;
                     mCachedImageLock.notify();
                     return;
                 }
@@ -100,13 +102,13 @@ public class ScreenCapturer {
 
     @Nullable
     public Image capture() {
-        if (mUnderUsingImage == null && mCachedImage == null) {
+        if (!mImageAvailable) {
             waitForImageAvailable();
         }
-        if (mCachedImage != null) {
-            if (mUnderUsingImage != null)
-                mUnderUsingImage.close();
-            synchronized (mCachedImageLock) {
+        synchronized (mCachedImageLock) {
+            if (mCachedImage != null) {
+                if (mUnderUsingImage != null)
+                    mUnderUsingImage.close();
                 mUnderUsingImage = mCachedImage;
                 mCachedImage = null;
             }
@@ -116,6 +118,9 @@ public class ScreenCapturer {
 
     private void waitForImageAvailable() {
         synchronized (mCachedImageLock) {
+            if (mImageAvailable) {
+                return;
+            }
             try {
                 mCachedImageLock.wait();
             } catch (InterruptedException e) {
diff --git a/autojs/src/main/java/com/stardust/autojs/runtime/api/Images.java b/autojs/src/main/java/com/stardust/autojs/runtime/api/Images.java
index c3460819..cf383e2c 100644
--- a/autojs/src/main/java/com/stardust/autojs/runtime/api/Images.java
+++ b/autojs/src/main/java/com/stardust/autojs/runtime/api/Images.java
@@ -103,7 +103,7 @@ public class Images {
             throw new SecurityException("No screen capture permission");
         }
         Image capture = mScreenCapturer.capture();
-        if (capture == mPreCapture) {
+        if (capture == mPreCapture && mPreCaptureImage != null) {
             return mPreCaptureImage;
         }
         mPreCapture = capture;