# DotView

- `Download example`

A simple one-window demo showing how to custom drawing in a custom `NSView`. Additionally shows how easy it is to embed a view in an `NSScrollView`, as well as how to use an `NSColorWell`.

## Sources

### DotView.py

    """DotView.py -- A one-window app demonstrating how to write a custom NSView.

    To build the demo program, run this line in Terminal.app:

        $ python setup.py py2app -A

    This creates a directory "dist" containing DotView.app. (The
    -A option causes the files to be symlinked to the .app bundle instead
    of copied. This means you don't have to rebuild the app if you edit the
    sources or nibs.)
    """

    # Created by Etienne Posthumus on Thu Dec 26 2002, after Apple's
    # ObjC DotView example.
    # Edited and enhanced by JvR, 2003.
    #
    # The main difference with the Apple DotView demo is that our custom view
    # is embedded in a scroll view. It turns out that this is almost no work
    # in InterfaceBuilder (select the view, then go to Layout -> Make subvies of
    # -> Scroll View), and *no* work in the code. It was too easy, so for kicks
    # I added zoom functionality and a "Show rulers" checkbox.

    import Cocoa
    import objc
    from objc import super
    from PyObjCTools import AppHelper

    ZOOM = 2.0

    # class defined in MainMenu.nib
    class DotView(Cocoa.NSView):
        colorWell = objc.IBOutlet()
        sizeSlider = objc.IBOutlet()

        def initWithFrame_(self, frame):
            self.center = (50.0, 50.0)
            super(DotView, self).initWithFrame_(frame)
            self.radius = 10.0
            self.color = Cocoa.NSColor.redColor()
            return self

        def awakeFromNib(self):
            self.colorWell.setColor_(self.color)
            self.sizeSlider.setFloatValue_(self.radius)
            scrollView = self.superview().superview()
            scrollView.setHasHorizontalRuler_(1)
            scrollView.setHasVerticalRuler_(1)

        @objc.IBAction
        def zoomIn_(self, sender):
            (x, y), (bw, bh) = self.bounds()
            (x, y), (fw, fh) = self.frame()
            self.setBoundsSize_((bw / ZOOM, bh / ZOOM))
            self.setFrameSize_((fw * ZOOM, fh * ZOOM))
            self.setNeedsDisplay_(True)

        @objc.IBAction
        def zoomOut_(self, sender):
            (x, y), (bw, bh) = self.bounds()
            (x, y), (fw, fh) = self.frame()
            self.setBoundsSize_((bw * ZOOM, bh * ZOOM))
            self.setFrameSize_((fw / ZOOM, fh / ZOOM))
            self.setNeedsDisplay_(True)

        @objc.IBAction
        def setRulersVisible_(self, button):
            scrollView = self.superview().superview()
            scrollView.setRulersVisible_(button.state())

        def isOpaque(self):
            return True

        def mouseDown_(self, event):
            eventLocation = event.locationInWindow()
            if event.modifierFlags() & Cocoa.NSCommandKeyMask:
                clipView = self.superview()
                self.originalPoint = eventLocation
                self.originalOffset = clipView.bounds()[0]
            else:
                self.center = self.convertPoint_fromView_(eventLocation, None)
                self.setNeedsDisplay_(True)
                self.autoscroll_(event)

        def mouseDragged_(self, event):
            if event.modifierFlags() & Cocoa.NSCommandKeyMask:
                clipView = self.superview()
                eventLocation = event.locationInWindow()
                ox, oy = self.originalPoint
                x, y = eventLocation
                dx, dy = x - ox, y - oy
                x, y = self.originalOffset
                ox, oy = clipView.constrainScrollPoint_((x - dx, y - dy))
                clipView.scrollToPoint_((ox, oy))
                clipView.superview().reflectScrolledClipView_(clipView)
            else:
                self.mouseDown_(event)

        def drawRect_(self, rect):
            Cocoa.NSColor.whiteColor().set()
            Cocoa.NSRectFill(self.bounds())
            origin = (self.center[0] - self.radius, self.center[1] - self.radius)
            size = (2 * self.radius, 2 * self.radius)
            dotRect = (origin, size)
            self.color.set()
            Cocoa.NSBezierPath.bezierPathWithOvalInRect_(dotRect).fill()

        @objc.IBAction
        def setRadius_(self, sender):
            self.radius = sender.floatValue()
            self.setNeedsDisplay_(True)

        @objc.IBAction
        def setColor_(self, sender):
            self.color = sender.color()
            self.setNeedsDisplay_(True)

    if __name__ == "__main__":
        AppHelper.runEventLoop()

### setup.py

    """
    Script for building the example.

    Usage:
        python3 setup.py py2app
    """
    from setuptools import setup

    setup(
        name="DotView",
        app=["DotView.py"],
        data_files=["English.lproj"],
        setup_requires=["py2app", "pyobjc-framework-Cocoa"],
    )