fix: [vnc]Fix display incorrect image issue

1. Skip the first image which may incomplete. 2. Add screen size changed callback in order to handle target phone rotated.

Log: Fix display incorrect image issue.

android/library/droidvnc-ng/libvncserver/include/rfb/rfbclient.h

@@ -239,6 +239,9 @@ typedef char* (*GetUserProc)(struct _rfbClient* client);
 typedef char* (*GetSASLMechanismProc)(struct _rfbClient* client, char* mechlist);
 #endif /* LIBVNCSERVER_HAVE_SASL */
 
+/** Callback when the screen size of the client has changed. */
+typedef void (*ScreenSizeChangedProc)(struct _rfbClient* client, int width, int height);
+
 typedef struct _rfbClient {
 	uint8_t* frameBuffer;
 	int width, height;
@@ -453,6 +456,9 @@ typedef struct _rfbClient {
 
 #endif /* LIBVNCSERVER_HAVE_SASL */
 
+	/** screen size changed nofication */
+	ScreenSizeChangedProc ScreenSizeChanged;
+
 #ifdef LIBVNCSERVER_HAVE_LIBZ
 #ifdef LIBVNCSERVER_HAVE_LIBJPEG
 	/** JPEG decoder state. */

android/library/droidvnc-ng/libvncserver/src/libvncclient/rfbclient.c

@@ -2136,6 +2136,7 @@ HandleRFBServerMessage(rfbClient* client)
             return FALSE;
           }
           rfbClientLog("Updated desktop size: %dx%d\n", rect.r.w, rect.r.h);
+          client->ScreenSizeChanged(client, rect.r.w, rect.r.h);
         }
         client->requestedResize = FALSE;
 

src/lib/cooperation/core/gui/phone/vncrecvthread.cpp

@@ -4,6 +4,7 @@
 
 #include "vncrecvthread.h"
 
+bool VNCRecvThread::_skipFirst = false;
 
 VNCRecvThread::VNCRecvThread(QObject *parent): QThread(parent)
 {
@@ -17,6 +18,7 @@ void VNCRecvThread::startRun(rfbClient *cl)
 
     _cl = cl;
     _cl->FinishedFrameBufferUpdate = frameBufferUpdated;
+    _cl->ScreenSizeChanged = screenSizeChanged;
     rfbClientSetClientData(_cl, nullptr, this);
     _runFlag = true;
 
@@ -29,9 +31,11 @@ void VNCRecvThread::stopRun()
         return;
 
     _runFlag = false;
+    _skipFirst = false;
     if (_cl) {
         rfbClientSetClientData(_cl, nullptr, nullptr);
         _cl->FinishedFrameBufferUpdate = nullptr;
+        _cl->ScreenSizeChanged = nullptr;
     }
 }
 
@@ -52,7 +56,19 @@ void VNCRecvThread::run()
 
 void VNCRecvThread::frameBufferUpdated(rfbClient *cl)
 {
+    if (!_skipFirst) {
+        // skip the first image buffer which may be incomplete
+        _skipFirst = true;
+        return;
+    }
     VNCRecvThread *vncRecvThread = static_cast<VNCRecvThread *>(rfbClientGetClientData(cl, nullptr));
 
     emit vncRecvThread->updateImageSignal(QImage(cl->frameBuffer, cl->width, cl->height, QImage::Format_RGBA8888));
 }
+
+void VNCRecvThread::screenSizeChanged(rfbClient *cl, int width, int height)
+{
+    VNCRecvThread *vncRecvThread = static_cast<VNCRecvThread *>(rfbClientGetClientData(cl, nullptr));
+
+    emit vncRecvThread->sizeChangedSignal(width, height);
+}

src/lib/cooperation/core/gui/phone/vncrecvthread.h

@@ -21,16 +21,20 @@ class VNCRecvThread : public QThread
     void stopRun();
 
     static void frameBufferUpdated(rfbClient *cl);
+    static void screenSizeChanged(rfbClient *cl, int width, int height);
 
 signals:
     void updateImageSignal(QImage);
+    void sizeChangedSignal(int width, int height);
 
 protected:
     void run() override;
 
 private:
     bool _runFlag = false;
     rfbClient *_cl;
+
+    static bool _skipFirst; // skip the first image
 };
 
 #endif // VNCRECVTHREAD_H

src/lib/cooperation/core/gui/phone/vncviewer.cpp

@@ -29,6 +29,9 @@ VncViewer::VncViewer(QWidget *parent)
       m_scaled(true),
       m_buttonMask(0)
 {
+    //init the background color
+    m_backgroundBrush = QBrush(Qt::black);
+
     setFocusPolicy(Qt::StrongFocus);
 #ifdef TOUCH_MODE
     setMouseTracking(false);
@@ -44,6 +47,7 @@ VncViewer::VncViewer(QWidget *parent)
 
     _vncRecvThread = new VNCRecvThread(this);
     connect(_vncRecvThread, &VNCRecvThread::updateImageSignal, this, &VncViewer::updateImage, Qt::BlockingQueuedConnection);
+    connect(_vncRecvThread, &VNCRecvThread::sizeChangedSignal, this, &VncViewer::onSizeChange, Qt::QueuedConnection);
     connect(_vncRecvThread, &VNCRecvThread::finished, this, &VncViewer::stop);
 
     m_frameTimer = new QTimer(this);
@@ -72,16 +76,19 @@ void VncViewer::frameTimerTimeout()
 #ifdef QT_DEBUG
     qWarning() << " FPS: " << currentFps();
 #endif
+}
 
+void VncViewer::onSizeChange(int width, int height)
+{
     if (!m_connected)
         return;
 
     // Check the screen has been rotated
-    int curentMode = (m_rfbCli->width < m_rfbCli->height) ? PORTRAIT : LANDSCAPE;
+    int curentMode = (width < height) ? PORTRAIT : LANDSCAPE;
     if (curentMode != m_phoneMode) {
         m_phoneMode = curentMode;
         int w = (m_phoneMode == PORTRAIT) ? m_realSize.width() : m_realSize.height();
-        const QSize size = {static_cast<int>(w * m_phoneScale), m_rfbCli->height};
+        const QSize size = {static_cast<int>(w * m_phoneScale), height};
 
         setSurfaceSize(size);
         emit sizeChanged(size);
@@ -154,6 +161,9 @@ void VncViewer::updateImage(const QImage &image)
 void VncViewer::paintEvent(QPaintEvent *event)
 {
     if (m_connected) {
+        if (m_image.isNull())
+            return;
+
         m_painter.begin(&m_surfacePixmap);
         // if (m_image.hasAlphaChannel()) {
         //     // 设置合成模式为源模式
@@ -169,7 +179,7 @@ void VncViewer::paintEvent(QPaintEvent *event)
 
         m_painter.begin(this);
         m_painter.setRenderHints(QPainter::SmoothPixmapTransform);
-        m_painter.fillRect(rect(), m_backgroundBrush);
+        m_painter.fillRect(rect(), backgroundBrush());
         if (scaled()) {
             m_surfaceRect.moveCenter(rect().center());
             m_painter.scale(m_scale, m_scale);

src/lib/cooperation/core/gui/phone/vncviewer.h

@@ -50,6 +50,7 @@ class VncViewer : public QWidget
 
 public slots:
     void frameTimerTimeout();
+    void onSizeChange(int width, int height);
     void onShortcutAction(int action);
 
     void updateSurface();