Basic error checking for debugger GL widget.

Currently the debugger segfaults if the GL context cannot be created.
This change allows the debugger to build with GL support, but still run if the
GL context cannot be created at runtime.

R=robertphillips@google.com

Review URL: https://codereview.chromium.org/18275002

git-svn-id: http://skia.googlecode.com/svn/trunk@9834 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 13 insertions, 8 deletions

diff --git a/debugger/QT/SkGLWidget.cpp b/debugger/QT/SkGLWidget.cpp
index 3dc60598ad..ae3155a4a6 100644
--- a/debugger/QT/SkGLWidget.cpp
+++ b/debugger/QT/SkGLWidget.cpp
@@ -29,6 +29,9 @@ SkGLWidget::~SkGLWidget() {
 
 void SkGLWidget::initializeGL() {
     fCurIntf = GrGLCreateNativeInterface();
+    if (!fCurIntf) {
+        return;
+    }
     fCurContext = GrContext::Create(kOpenGL_GrBackend, (GrBackendContext) fCurIntf);
     GrBackendRenderTargetDesc desc = this->getDesc(this->width(), this->height());
     desc.fOrigin = kBottomLeft_GrSurfaceOrigin;
@@ -43,19 +46,21 @@ void SkGLWidget::initializeGL() {
 }
 
 void SkGLWidget::resizeGL(int w, int h) {
-    GrBackendRenderTargetDesc desc = this->getDesc(w, h);
-    desc.fOrigin = kBottomLeft_GrSurfaceOrigin;
-    GrRenderTarget* curRenderTarget = fCurContext->wrapBackendRenderTarget(desc);
-    SkSafeUnref(fGpuDevice);
-    SkSafeUnref(fCanvas);
-    fGpuDevice = new SkGpuDevice(fCurContext, curRenderTarget);
-    fCanvas = new SkCanvas(fGpuDevice);
+    if (fCurContext) {
+        GrBackendRenderTargetDesc desc = this->getDesc(w, h);
+        desc.fOrigin = kBottomLeft_GrSurfaceOrigin;
+        GrRenderTarget* curRenderTarget = fCurContext->wrapBackendRenderTarget(desc);
+        SkSafeUnref(fGpuDevice);
+        SkSafeUnref(fCanvas);
+        fGpuDevice = new SkGpuDevice(fCurContext, curRenderTarget);
+        fCanvas = new SkCanvas(fGpuDevice);
+    }
     fDebugger->resize(w, h);
     draw();
 }
 
 void SkGLWidget::paintGL() {
-    if (!this->isHidden()) {
+    if (!this->isHidden() && fCanvas) {
         fDebugger->draw(fCanvas);
         // TODO(chudy): Implement an optional flush button in Gui.
         fCanvas->flush();