Canvas: do not emit paint when resized but hidden

It turns out to be a bad idea (as in, breaks the enterprise controls)
to block paint() altogether when hidden. The original bug report
QTBUG-31830 only complained about paint() being emitted upon resize
while _hidden_, so this change solves exactly that. User is still
free to call requestPaint() even when hidden, and Canvas now doesn't
recklessly ignore the request.

Task-number: QTBUG-31830
Change-Id: Icd82188f65406b3ef6ae3b19b5984944576886ff
Reviewed-by: Jens Bache-Wiig <jens.bache-wiig@digia.com>
Reviewed-by: Mitch Curtis <mitch.curtis@digia.com>
Reviewed-by: Gunnar Sletta <gunnar.sletta@jollamobile.com>

1 files changed, 4 insertions, 5 deletions

diff --git a/src/quick/items/context2d/qquickcanvasitem.cpp b/src/quick/items/context2d/qquickcanvasitem.cpp
index 17adf1b66b..8b9ad50a3f 100644
--- a/src/quick/items/context2d/qquickcanvasitem.cpp
+++ b/src/quick/items/context2d/qquickcanvasitem.cpp
@@ -590,8 +590,10 @@ void QQuickCanvasItem::geometryChanged(const QRectF &newGeometry, const QRectF &
         emit canvasWindowChanged();
     }
 
-    if (d->available && newSize != oldGeometry.size())
-        requestPaint();
+    if (d->available && newSize != oldGeometry.size()) {
+        if (isVisible() || (d->extra.isAllocated() && d->extra->effectRefCount > 0))
+            requestPaint();
+    }
 }
 
 void QQuickCanvasItem::releaseResources()
@@ -640,9 +642,6 @@ void QQuickCanvasItem::updatePolish()
     QQuickItem::updatePolish();
 
     Q_D(QQuickCanvasItem);
-    if (!isVisible() && !(d->extra.isAllocated() && d->extra->effectRefCount>0))
-        return;
-
     if (d->context && d->renderStrategy != QQuickCanvasItem::Cooperative)
         d->context->prepare(d->canvasSize.toSize(), d->tileSize, d->canvasWindow.toRect(), d->dirtyRect.toRect(), d->smooth, antialiasing());