Consistently use QGLShareContextScope for context switching

QGLShareContextScope is safer and more reliable than trying to manually
detect how and when to temporarily switch contexts.  Replace the few
remaining instances of context-switching with it.

Reviewed-by: trustme

3 files changed, 3 insertions, 15 deletions

diff --git a/src/opengl/gl2paintengineex/qglengineshadermanager.cpp b/src/opengl/gl2paintengineex/qglengineshadermanager.cpp
index 59c50aa..e22303d 100644
--- a/src/opengl/gl2paintengineex/qglengineshadermanager.cpp
+++ b/src/opengl/gl2paintengineex/qglengineshadermanager.cpp
@@ -60,12 +60,8 @@ QGLEngineSharedShaders *QGLEngineSharedShaders::shadersForContext(const QGLConte
 {
     QGLEngineSharedShaders *p = reinterpret_cast<QGLEngineSharedShaders *>(qt_shared_shaders()->value(context));
     if (!p) {
-        QGLContext *oldContext = const_cast<QGLContext *>(QGLContext::currentContext());
-        if (oldContext != context)
-            const_cast<QGLContext *>(context)->makeCurrent();
+        QGLShareContextScope scope(context);
         qt_shared_shaders()->insert(context, p = new QGLEngineSharedShaders(context));
-        if (oldContext && oldContext != context)
-            oldContext->makeCurrent();
     }
     return p;
 }
diff --git a/src/opengl/gl2paintengineex/qglgradientcache.cpp b/src/opengl/gl2paintengineex/qglgradientcache.cpp
index 4b2b2a0..e06f15d 100644
--- a/src/opengl/gl2paintengineex/qglgradientcache.cpp
+++ b/src/opengl/gl2paintengineex/qglgradientcache.cpp
@@ -57,13 +57,9 @@ QGL2GradientCache *QGL2GradientCache::cacheForContext(const QGLContext *context)
 {
     QGL2GradientCache *p = reinterpret_cast<QGL2GradientCache *>(qt_gradient_caches()->value(context));
     if (!p) {
-        QGLContext *oldContext = const_cast<QGLContext *>(QGLContext::currentContext());
-        if (oldContext != context)
-            const_cast<QGLContext *>(context)->makeCurrent();
+        QGLShareContextScope scope(context);
         p = new QGL2GradientCache;
         qt_gradient_caches()->insert(context, p);
-        if (oldContext && oldContext != context)
-            oldContext->makeCurrent();
     }
     return p;
 }
diff --git a/src/opengl/gl2paintengineex/qpaintengineex_opengl2.cpp b/src/opengl/gl2paintengineex/qpaintengineex_opengl2.cpp
index 992d47d..073f7db 100644
--- a/src/opengl/gl2paintengineex/qpaintengineex_opengl2.cpp
+++ b/src/opengl/gl2paintengineex/qpaintengineex_opengl2.cpp
@@ -162,15 +162,11 @@ QGLTextureGlyphCache::QGLTextureGlyphCache(QGLContext *context, QFontEngineGlyph
 QGLTextureGlyphCache::~QGLTextureGlyphCache()
 {
     if (ctx) {
-        QGLContext *oldContext = const_cast<QGLContext *>(QGLContext::currentContext());
-        if (oldContext != ctx)
-            ctx->makeCurrent();
+        QGLShareContextScope scope(ctx);
         glDeleteFramebuffers(1, &m_fbo);
 
         if (m_width || m_height)
             glDeleteTextures(1, &m_texture);
-        if (oldContext && oldContext != ctx)
-            oldContext->makeCurrent();
     }
 }