How do you make a QGraphicsScene with a specified size and a QGraphicsView to monitor that scene with the same size?
This sounds like a stupid question but consider the following test code [1]
import sys
from PyQt4 import QtGui, QtCore
class MainWindow(QtGui.QMainWindow):
def __init__(self):
QtGui.QMainWindow.__init__(self)
self.scene = QtGui.QGraphicsScene(0, 0, 200, 200, self)
self.view = QtGui.QGraphicsView(self.scene, self)
#self.view.setMaximumSize(200, 200)
self.setCentralWidget(self.view)
if __name__ == '__main__':
app = QtGui.QApplication(sys.argv)
win = MainWindow()
win.show()
sys.exit(app.exec_())
When I run this I get a little window with the QGraphicsView and no scroll bars. If I shrink the window scroll bars appear because I've made the view smaller than the specified size of the scene. If I enlarge the window the bars go away and the view resizes with the window. All of this makes sense.
Now I run the same code again but with the commented line (preceded by #) un-commented. The Window appears with the view inside, but the view has scroll bars. When I shrink the window the view also shrinks, but when I enlarge the window the view only enlarges to a certain size. This is not surprising. What is surprising is that with the view at it's maximum size, the scroll bars are still there. I don't understand this because the maximum size of the view is explicitly matched to the size of the scene in the code.
Why does this happen?
I am aware that other questions have explained how to force the scene and view to fit together but I want to understand what size view and scene I have actually made, hence my attempt to use explicitly specified sizes.
[1] I'm using PyQt, C++ users just read "self" as "this" and "import" as "#include"
EDIT: The accepted answer below is absolutely correct. I would just like to add for others who read this that if your view is in a layout you have to account for the layout margins as well. These can be explicitly set in the QtDesigner etc.
