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, 20 insertions, 12 deletions

diff --git a/tests/auto/quick/qquickcanvasitem/data/tst_canvas.qml b/tests/auto/quick/qquickcanvasitem/data/tst_canvas.qml
index b92f6354a5..d90eb3971e 100644
--- a/tests/auto/quick/qquickcanvasitem/data/tst_canvas.qml
+++ b/tests/auto/quick/qquickcanvasitem/data/tst_canvas.qml
@@ -180,20 +180,28 @@ CanvasTestCase {
        tryCompare(c, "availableChangedCount", 1);
        //scene graph could be available immediately
        //in this case, we force waiting a short while until the init paint finished
-       if (c.visible) {
-           tryCompare(c, "paintedCount", 1);
-       } else {
-           tryCompare(c, "paintedCount", 0);
-       }
+       tryCompare(c, "paintedCount", 1);
        ctx.fillRect(0, 0, c.width, c.height);
        c.toDataURL();
-       if (c.visible) {
-           tryCompare(c, "paintCount", 1);
-           tryCompare(c, "paintedCount", 2);
-       } else {
-           tryCompare(c, "paintCount", 0);
-           tryCompare(c, "paintedCount", 1);
-       }
+       tryCompare(c, "paintedCount", 2);
+       tryCompare(c, "paintCount", 1);
+       // implicit repaint when visible and resized
+       testCase.visible = true;
+       c.width += 1;
+       c.height += 1;
+       tryCompare(c, "paintCount", 2);
+       tryCompare(c, "paintedCount", 2);
+       // allow explicit repaint even when hidden
+       testCase.visible = false;
+       c.requestPaint();
+       tryCompare(c, "paintCount", 3);
+       tryCompare(c, "paintedCount", 2);
+       // no implicit repaint when resized but hidden
+       c.width += 1;
+       c.height += 1;
+       waitForRendering(c);
+       compare(c.paintCount, 3);
+       tryCompare(c, "paintedCount", 2);
        c.destroy();
   }
    function test_loadImage(row) {