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import pygtk |
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pygtk.require('2.0') |
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|
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import math |
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import gtk |
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import cairo |
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|
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from gaphas.item import Item |
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from gaphas.state import observed, reversible_property, disable_dispatching |
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from gaphas.tool import HandleTool |
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|
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from gaphas import GtkView, View |
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from gaphas.item import Line, SW, NE, NW, SE, Element, Handle |
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from gaphas.tool import Tool, HoverTool, PlacementTool, HandleTool, ToolChain |
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from gaphas.tool import ItemTool, RubberbandTool |
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from gaphas.geometry import point_on_rectangle, distance_rectangle_point |
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from gaphas.constraint import LineConstraint, LessThanConstraint, EqualsConstraint, Constraint, _update, BalanceConstraint |
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from gaphas.canvas import CanvasProjection |
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from gaphas.solver import Variable, solvable, WEAK, NORMAL, STRONG, VERY_STRONG |
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|
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from gaphas.painter import ItemPainter |
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from gaphas import state |
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from gaphas.util import text_extents |
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|
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from gaphas import painter |
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|
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from blockcanvas import * |
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from panzoom import * |
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#painter.DEBUG_DRAW_BOUNDING_BOX = True |
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|
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#------------------------------------------------------------------------------ |
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|
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class Port(object): |
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""" |
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Ports are special places onto which Handles can be connected, specifically |
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when users are drawing 'connector' lines between modelling 'blocks'. |
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|
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A subclass of Item called 'Block' will be given the ability to store |
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an array of these Ports, in such a way that gluing methods will be able to |
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select appropriate ports for a given connector line. The Ports also give |
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data about where these available connected are located graphically, in the |
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Block's local coordinate system. |
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|
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It is not intended that the number or location of ports would be editable |
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once a port is instantiated. Only the connection of a port to a handle |
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is editable by the user. |
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|
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It is intended that subclasses to the Port class would be created to provide |
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finer control over whether or not a certain handle can be permitted to |
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connect to any given port. |
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|
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Attributes: |
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- block: Block to which Port belongs |
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- connected_to: Handle to which port is connected, if any |
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- x: port x-location in item's local coordinate system |
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- y: port y-location in item's local coordinate system |
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|
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Private: |
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- _x: port x-location in item's local coordinate system |
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- _y: port y-location in item's local coordinate system |
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- _connected_to: Handle to which port is connected, if any |
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""" |
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|
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_x = solvable() |
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_y = solvable() |
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|
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def __init__(self, block, strength = STRONG): |
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self.block = block |
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self._x.strength = strength |
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self._y.strength = strength |
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self._connected_to = None |
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|
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@observed |
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def _set_x(self, x): |
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self._x = x |
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|
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x = reversible_property(lambda s: s._x, _set_x, bind={'x': lambda self: float(self.x) }) |
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disable_dispatching(_set_x) |
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|
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@observed |
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def _set_y(self, y): |
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self._y = y |
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|
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y = reversible_property(lambda s: s._y, _set_y, bind={'y': lambda self: float(self.y) }) |
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disable_dispatching(_set_y) |
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|
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@observed |
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def _set_connected_to(self, connected_to): |
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self._connected_to = connected_to |
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|
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connected_to = reversible_property(lambda s: s._connected_to, |
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_set_connected_to) |
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|
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def draw(self, context): |
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""" |
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Render the item to a canvas view. |
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Context contains the following attributes: |
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|
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- cairo: the Cairo Context use this one to draw |
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- view: the view that is to be rendered to |
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- selected, focused, hovered, dropzone: view state of items (True/False) |
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- draw_all: a request to draw everything, for bounding box calculation |
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""" |
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pass |
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|
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def point(self, x, y): |
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""" |
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Get the distance from a point (``x``, ``y``) to the item. |
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``x`` and ``y`` are in item coordinates. |
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|
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Defined here because a port is just a 'point' at this stage. |
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""" |
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return math.sqrt((x-self.x)**2 + (y-self.y)**2) |
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|
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@observed |
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def _set_pos(self, pos): |
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""" |
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Set handle position (Item coordinates). |
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""" |
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self.x, self.y = pos |
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|
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pos = property(lambda s: (s.x, s.y), _set_pos) |
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|
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class PointConstraint(Constraint): |
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""" |
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Ensure that point B is always kept on top of point A |
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|
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Attributes: |
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_A: first point, defined by (x,y) |
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_B: second point, defined by (x,y) |
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""" |
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|
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def __init__(self, A, B): |
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print "A =",A |
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print "A[0] =",A[0].variable() |
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print "A[0].strength =",A[0].variable().strength |
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|
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print "B =",B |
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print "B[0] =",B[0].variable() |
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print "B[0].strength =",B[0].variable().strength |
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|
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# assert isinstance(p1[0],Variable) |
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# assert isinstance(p1[1],Variable) |
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# assert isinstance(p2[0],Variable) |
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# assert isinstance(p2[1],Variable) |
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|
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super(PointConstraint, self).__init__(A[0],A[1],B[0],B[1]) |
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self._A = A |
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self._B = B |
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|
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def solve_for(self, var=None): |
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print "Solving PointConstraint",self,"for var",var |
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|
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_update(self._B[0], self._A[0].value) |
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_update(self._B[1], self._A[1].value) |
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|
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class Block(Element): |
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""" |
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This is an ASCEND 'block' in the canvas-based modeller. The block will have |
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sets of input and output ports to which connector lines can be 'glued'. |
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The block will also have a corresponding ASCEND MODEL type, and a name |
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which will be used in ASCEND to refer to this block. Each of the ports will |
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be special visual elements, but note that these are not 'handles', because |
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they can not be used to resize/modify the element. |
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""" |
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|
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def __init__(self, label="unnamed", width=64, height=64): |
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|
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self.ports = [] |
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self.label = label |
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super(Block, self).__init__(width, height) |
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|
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def draw(self, context): |
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#print 'Box.draw', self |
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c = context.cairo |
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nw = self._handles[NW] |
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c.rectangle(nw.x, nw.y, self.width, self.height) |
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if context.hovered: |
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c.set_source_rgba(.8,.8,1, .8) |
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else: |
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c.set_source_rgba(1,1,1, .8) |
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c.fill_preserve() |
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c.set_source_rgb(0,0,0.8) |
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c.stroke() |
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|
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phalfsize = 3 |
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for p in self.ports: |
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c.rectangle(p.x - phalfsize, p.y - phalfsize, 2*phalfsize, 2*phalfsize) |
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if p.connected_to is None: |
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c.set_source_rgba(0.8,0.8,1, 0.8) |
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else: |
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c.set_source_rgba(1,0,0,1) |
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c.fill_preserve() |
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c.set_source_rgb(0.8,0.8,0) |
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c.stroke() |
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|
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def glue(self,item, handle, ix, iy): |
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gluerange = 10 |
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mindist = -1; |
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minport = None |
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for p in self.ports: |
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dist = math.sqrt((ix-p.x)**2 + (iy-p.y)**2) |
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if dist < gluerange: |
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if not minport or dist<mindist: |
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mindist = dist |
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minport = p |
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return mindist, minport |
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|
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def pre_update(self,context): |
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print "PRE-UPDATE BLOCK" |
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|
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class DefaultBlock(Block): |
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""" |
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This is a 'default block' with a certain number of input and output ports |
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shown depending on the values sent to __init__. It is drawn as a simple |
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box with the input ports on the left and the output ports on the right. |
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""" |
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|
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def __init__(self, label="unnamed", width=64, height=64, inputs=2, outputs=3): |
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|
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super(DefaultBlock, self).__init__(label, width, height) |
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|
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eq = EqualsConstraint |
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bal = BalanceConstraint |
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handles = self._handles |
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h_nw = handles[NW] |
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h_ne = handles[NE] |
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h_sw = handles[SW] |
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h_se = handles[SE] |
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|
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for i in range(inputs): |
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p = Port(self) |
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self.ports.append(p) |
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self._constraints.append(eq(p.x, h_nw.x)) |
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self._constraints.append(bal(band=(h_nw.y, h_sw.y),v=p.y, balance=(0.5 + i)/inputs)) |
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|
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for i in range(outputs): |
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p = Port(self) |
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self.ports.append(p) |
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self._constraints.append(eq(p.x, h_ne.x)) |
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self._constraints.append(bal(band=(h_ne.y,h_se.y),v=p.y, balance=(0.5 + i)/outputs)) |
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|
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def draw(self, context): |
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# draw the box itself |
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c = context.cairo |
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nw = self._handles[NW] |
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c.rectangle(nw.x, nw.y, self.width, self.height) |
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if context.hovered: |
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c.set_source_rgba(.8,.8,1, .8) |
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else: |
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c.set_source_rgba(1,1,1, .8) |
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c.fill_preserve() |
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c.set_source_rgb(0,0,0.8) |
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c.stroke() |
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|
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# now the draw the ports using the base class |
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super(DefaultBlock, self).draw(context) |
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|
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class PortConnectingHandleTool(HandleTool): |
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""" |
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This is a HandleTool which supports the connection of lines to the Ports |
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of Blocks, for the purpose of building up process flow diagrams, control |
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diagrams, etc, for the proposed canvas-based modeller of ASCEND. |
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""" |
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|
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def glue(self, view, item, handle, wx, wy): |
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""" |
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This allows the tool to glue a handle to any connectable Port of a Block. |
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The distance from the item to the handle is determined in canvas |
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coordinates, using a 10 pixel glue distance. |
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|
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Returns the closest Port that is within the glue distance. |
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""" |
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if not handle.connectable: |
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return |
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|
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# Make glue distance depend on the zoom ratio (should be about 10 pixels) |
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inverse = cairo.Matrix(*view.matrix) |
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inverse.invert() |
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#glue_distance, dummy = inverse.transform_distance(10, 0) |
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glue_distance = 10 |
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glue_port = None |
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glue_point = None |
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#print "Gluing..." |
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for i in view.canvas.get_all_items(): |
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if not hasattr(i,'ports'): |
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continue |
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if not i is item: |
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#print "Trying glue to",i |
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v2i = view.get_matrix_v2i(i).transform_point |
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ix, iy = v2i(wx, wy) |
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distance, port = i.glue(item, handle, ix, iy) |
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# Transform distance to world coordinates |
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#distance, dumy = matrix_i2w(i).transform_distance(distance, 0) |
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if not port is None and distance <= glue_distance: |
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glue_distance = distance |
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i2v = view.get_matrix_i2v(i).transform_point |
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glue_point = i2v(port.x, port.y) |
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glue_port = port |
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else: |
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print "i is item" |
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if glue_point: |
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v2i = view.get_matrix_v2i(item).transform_point |
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handle.x, handle.y = v2i(*glue_point) |
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#print "Found glue point ",handle.x,handle.y |
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return glue_port |
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|
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def connect(self, view, item, handle, wx, wy): |
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""" |
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Connect a handle to a port. 'item' is the line to which the handle |
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belongs; wx and wy are the location of the cursor, so we run the 'glue' |
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routine to find the desired gluing point, then make the connection to |
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the object which 'glue' returns, which will be a Port object (in the |
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context of this tool). |
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|
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In this "method" the following assumptios are made: |
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1. Only ``Port``s of ``Block``s will accept connections from handles. |
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2. The only items with connectable handles are ``Line``s |
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|
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""" |
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|
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# create a special local handle_disconnect function |
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def handle_disconnect(): |
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try: |
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view.canvas.solver.remove_constraint(handle.connection_data) |
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except KeyError: |
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print 'constraint was already removed for', item, handle |
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pass # constraint was alreasy removed |
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else: |
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print 'constraint removed for', item, handle |
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handle.connected_port.connected_to = None |
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handle.connection_data = None |
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handle.connection_port = None |
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handle.connected_to = None |
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|
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# Remove disconnect handler: |
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handle.disconnect = lambda: 0 |
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|
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#print 'Handle.connect', view, item, handle, wx, wy |
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glue_port = self.glue(view, item, handle, wx, wy) |
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|
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if glue_port and hasattr(handle,'connected_port') and handle.connected_port is glue_port: |
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try: |
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view.canvas.solver.remove_constraint(handle.connection_data) |
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except KeyError: |
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pass |
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else: |
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# ie no glue_port found, or the handle connected to something else |
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if handle.connected_to: |
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handle.disconnect() |
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|
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if glue_port: |
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if isinstance(glue_port, Port): |
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print "Gluing to port",glue_port |
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|
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print "handle.pos =",handle.pos |
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print "glue_port =",glue_port |
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print "glue_port.pos = ",glue_port.pos |
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print "glue_port.block =",glue_port.block |
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|
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handle.connection_data = PointConstraint( |
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B=CanvasProjection(handle.pos,item) |
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,A=CanvasProjection(glue_port.pos, glue_port.block) |
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) |
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view.canvas.solver.add_constraint(handle.connection_data) |
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#glue_port.block._constraints.append(handle.connection_data) |
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|
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handle.connected_to = glue_port.block |
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handle.connected_port = glue_port |
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handle.disconnect = handle_disconnect |
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glue_port.connected_to = handle |
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|
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def disconnect(self, view, item, handle): |
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if handle.connected_to: |
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print 'Handle.disconnect', view, item, handle |
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view.canvas.solver.remove_constraint(handle.connection_data) |
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|
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|
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|
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# vim: sw=4:et:ai |
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