| Guido van Rossum | 2e44967 | 1990-11-05 19:44:36 +0000 | [diff] [blame^] | 1 | # A class that sits transparently between a parent and one child. |
| 2 | # First create the parent, then this thing, then the child. |
| 3 | # Use this as a base class for objects that are almost transparent. |
| 4 | # Don't use as a base class for parents with multiple children. |
| 5 | |
| 6 | Error = 'TransParent.Error' # Exception |
| 7 | |
| 8 | class ManageOneChild(): |
| 9 | # |
| 10 | # Upcalls shared with other single-child parents |
| 11 | # |
| 12 | def addchild(self, child): |
| 13 | if self.child: |
| 14 | raise Error, 'addchild: one child only' |
| 15 | if not child: |
| 16 | raise Error, 'addchild: bad child' |
| 17 | self.child = child |
| 18 | # |
| 19 | def delchild(self, child): |
| 20 | if not self.child: |
| 21 | raise Error, 'delchild: no child' |
| 22 | if child <> self.child: |
| 23 | raise Error, 'delchild: not my child' |
| 24 | self.child = 0 |
| 25 | |
| 26 | class TransParent() = ManageOneChild(): |
| 27 | # |
| 28 | # Calls from creator |
| 29 | # NB derived classes may add parameters to create() |
| 30 | # |
| 31 | def create(self, parent): |
| 32 | parent.addchild(self) |
| 33 | self.parent = parent |
| 34 | self.child = 0 # No child yet |
| 35 | # |
| 36 | # Downcalls from parent to child |
| 37 | # |
| 38 | def destroy(self): |
| 39 | del self.parent |
| 40 | if self.child: self.child.destroy() |
| 41 | del self.child |
| 42 | # |
| 43 | def minsize(self, m): |
| 44 | if not self.child: |
| 45 | return 0, 0 |
| 46 | else: |
| 47 | return self.child.minsize(m) |
| 48 | def getbounds(self, bounds): |
| 49 | if not self.child: |
| 50 | raise Error, 'getbounds w/o child' |
| 51 | else: |
| 52 | return self.child.getbounds() |
| 53 | def setbounds(self, bounds): |
| 54 | if not self.child: |
| 55 | raise Error, 'setbounds w/o child' |
| 56 | else: |
| 57 | self.child.setbounds(bounds) |
| 58 | def draw(self, args): |
| 59 | if self.child: |
| 60 | self.child.draw(args) |
| 61 | # |
| 62 | # Downcalls only made after certain upcalls |
| 63 | # |
| 64 | def mouse_down(self, detail): |
| 65 | if self.child: self.child.mouse_down(detail) |
| 66 | def mouse_move(self, detail): |
| 67 | if self.child: self.child.mouse_move(detail) |
| 68 | def mouse_up(self, detail): |
| 69 | if self.child: self.child.mouse_up(detail) |
| 70 | # |
| 71 | def timer(self): |
| 72 | if self.child: self.child.timer() |
| 73 | # |
| 74 | # Upcalls from child to parent |
| 75 | # |
| 76 | def need_mouse(self, child): |
| 77 | self.parent.need_mouse(self) |
| 78 | def no_mouse(self, child): |
| 79 | self.parent.no_mouse(self) |
| 80 | # |
| 81 | def need_timer(self, child): |
| 82 | self.parent.need_timer(self) |
| 83 | def no_timer(self, child): |
| 84 | self.parent.no_timer(self) |
| 85 | # |
| 86 | def begindrawing(self): |
| 87 | return self.parent.begindrawing() |
| 88 | def beginmeasuring(self): |
| 89 | return self.parent.beginmeasuring() |
| 90 | # |
| 91 | def change(self, area): |
| 92 | self.parent.change(area) |
| 93 | def scroll(self, args): |
| 94 | self.parent.scroll(args) |
| 95 | def settimer(self, itimer): |
| 96 | self.parent.settimer(itimer) |