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class TrivalentGraphDrawingTool_OBS(Tool): # REVIEW: can it turn into HuntForNode with node = None to save coding?
#doc - Active means we know the parent (pane or widget) as self.pane;
# the pane is also what distributes events... it does so through the tool, on its event handler stack
# handlers for when we're applied to a pane
def on_mouse_press(self, x, y, button, modifiers):
# todo: care about button, modifiers
# todo: if an edge is being drawn, complete it? no, some other handler did that, then returned None to pass event to us.
pane = self.pane
model = pane.model #k
obj = pane.find_object(x, y) # TODO: move this into COMMON CODE with an on_draw_handle method
node = None # node we hit or made
if not obj:
# empty space
node = model.cmd_addNode(x, y)
elif isinstance(obj, model.Node):
node = obj
elif isinstance(obj, model.Edge):
node = model.cmd_addNodeOnEdge(x, y, obj)
# drag this node around, while mouse is down,
# then (in some cases) draw an edge from it when mouse is up
should_draw_edge = len(node.edges) < 3
# todo: better: if hit node you are already indirectly connected to, draw edge and stop;
# otherwise draw edge and continue.
## handler = DragNodeThenHuntForNode(node, x, y)
# define handlers here in order in which they execute in time:
handler1 = DragNode(pane, node, x, y)
if should_draw_edge:
handler2 = HuntForNode(pane, node)
pane.push_handlers(handler2)
pane.push_handlers(handler1) # this runs, then pops to uncover other one
#k: what if 1st one changes mind about running 2nd one?
#e clearly we need some sort of expr for a state diagram for things to run in pane...
return EVENT_HANDLED
def on_mouse_motion(self, x, y, dx, dy):
# todo: highlight
pass
pass
###k syntax for this "command description" (DragNode, CMD_RETVAL) (a class with some init args)
# DECIDE: should we just return something like tool.DragNode(self.node) instead?
# that's already an instance, but it's inactive until put into the right place...
# but as optim, note that this is usually discarded (during mouse motion)...
# otoh that class would not be too slow to instantiate.
# BUT it can't say self.node, it needs CMD_RETVAL and later subst of that...
# so nevermind for now.
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