how to Fit QGraphicsScene in a QGraphicsView

Question

I want to to fit a QGraphicsScene in a QGraphicsView with different dimensions, such that it will shrink or expand according to size of view, and there should be no any scrollbar.

Does this answer your question? [Qt GraphicsView stretch scene to fit](https://stackoverflow.com/questions/3942581/qt-graphicsview-stretch-scene-to-fit) — Abderrahmene Rayene Mihoub, Jul 14 '23 at 19:21

score 12 · Answer 1 · edited Jul 15 '23 at 12:06

12

This worked for me:

void MyGraphicsView::zoomToFit()
{
    fitInView(scene()->sceneRect(), Qt::KeepAspectRatio);
}

You might want to adjust the scene rectangle to have a little margin; might look better, depending on your content.

edited Jul 15 '23 at 12:06

Abderrahmene Rayene Mihoub

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answered Oct 08 '14 at 22:43

ssc

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score 5 · Accepted Answer · edited Nov 06 '15 at 07:08

5

scaling the view like bellow doing what required:

view->scale(frameWidth / sceneWidth, frameHeight / sceneHeight);

edited Nov 06 '15 at 07:08

Vincent Duprez

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answered Jun 11 '12 at 07:37

anj

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How can I get frameWidth/sceneWidth/ etc? – Dariusz Feb 19 '17 at 00:36

score 4 · Answer 3 · edited Jul 27 '23 at 23:23

4

view->setSceneRect(0, 0, view->frameSize().width(), view->frameSize().height());

Connect this piece of code with resizeEvent of QGraphicsView

If you set scene rect with size greater than view's, scroll bars will appear. Else if you set scene rect equal to view's frame width or less, no scroll bars will be there.

Then I guess QGraphicsView::fitInView() is your solution.

edited Jul 27 '23 at 23:23

chrysante

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answered Jun 05 '12 at 07:21

ScarCode

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It Will just reset sceneRect, i.e. it will crop extra part which is out side of this rect, but didnt shrink it – anj Jun 06 '12 at 04:52

score 0 · Answer 4 · answered May 07 '19 at 00:31

I know this doesn't answer the question, but this is at the top of google when searching for how to fit the contents to the view. It's simply:

def fit_contents(self):
    items = self.scene().items()
    rects = [item.mapToScene(item.boundingRect()).boundingRect() for item in items]
    rect = min_bounding_rect(rects)
    self.setSceneRect(rect)

Where min_bounding_rect is:

def min_bounding_rect(rectList):
if rectList == []:
    return None

minX = rectList[0].left()
minY = rectList[0].top()
maxX = rectList[0].right()
maxY = rectList[0].bottom()

for k in range(1, len(rectList)):
    minX = min(minX, rectList[k].left())
    minY = min(minY, rectList[k].top())
    maxX = max(maxX, rectList[k].right())
    maxY = max(maxY, rectList[k].bottom())

return QRectF(minX, minY, maxX-minX, maxY-minY)

how to Fit QGraphicsScene in a QGraphicsView

4 Answers4