NAME¶
GraphicView, GraphicViews - base classes for graphical component views
SYNOPSIS¶
#include <Unidraw/Components/grview.h>
DESCRIPTION¶
GraphicView is an abstract base class for graphical views of GraphicComp
objects. GraphicView is derived from ComponentView and adds operations for
manipulating its graphical attributes. GraphicViews is a non-abstract subclass
of GraphicView for composite graphical component views.
GRAPHICVIEW PUBLIC OPERATIONS¶
- virtual void Interpret(Command*)
- virtual void Uninterpret(Command*)
- GraphicView objects can (un)interpret the following command:
AlignToGridCmd aligns the graphical component to the grid that
affects the view. Interpret uses AlignToGridCmd::Align to carry out the
alignment, while Uninterpret uses AlignToGridCmd::Unalign to reverse
Interpret's effects.
- virtual void DrawHandles()
- virtual void RedrawHandles()
- virtual void InitHandles()
- virtual void EraseHandles()
- Operations for displaying and hiding the view's selection handles. All use
CreateHandles (described below) to create component-specific rubberbands
that draw the handles if they do not already exist. The rubberband is
stored in the _handles protected member. DrawHandles makes the
handles visible if they are not already visible. RedrawHandles forces the
handles to draw themselves even if they are already drawn, which may make
them disappear if the rubberband draws them in XOR mode. InitHandles
deletes and recreates the rubberband defining the handles if it existed
when InitHandles was called. EraseHandles erases the handles and deletes
the rubberband.
- virtual Manipulator* CreateManipulator(
- Viewer*, Event&, Transformer*, Tool*
- )
- virtual void InterpretManipulator(Manipulator*)
- Operations that define how the GraphicView reacts when it is manipulated
by a tool and how the tool affects that component following manipulation.
They effectively override the tool's default behavior if the tool defers
manipulator creation and interpretation to the view. This allows the same
tool to behave differently depending on the component it manipulates.
CreateManipulator creates a manipulator that is appropriate for the given
tool. It receives the viewer in which the manipulation will take place, an
event with which to initialize the manipulator if necessary, and the
coordinate transformation that maps canvas coordinates into the subject's
coordinate space. InterpretManipulator is called following manipulation
and defines how to construct a command that carries out the manipulation's
desired effect. GraphicView objects create and interpret manipulators for
the following tools:
GraphicCompTool will let the user position a fixed-sized outline
reflecting the view's bounding box on the screen. Interpretation will
produce a command that inserts a copy of the subject into the editor's
component at the specified position. Placement will be constrained by
gravity, if active.
MoveTool will let the user move a fixed-sized outline reflecting the
view's bounding box on the screen. Interpretation will produce a command
that moves the subject to the specified position. Holding down the Shift
key will constrain the movement to purely horizontal or vertical, and
movement will be constrained by gravity.
ScaleTool will let the user drag a scaling rectangular outline
corresponding to the view's scale following manipulation with the tool.
Scaling will be constrained by gravity.
StretchTool will let the user drag a variable-sized rectangular
outline corresponding to a two-dimensional stretch that the component will
undergo following manipulation. Holding the Shift key down will constrain
the stretch to one dimension. Stretching will be constrained by gravity.
RotateTool will let the user rotate a fixed-sized rectangular outline
reflecting the view's bounding box. The rotation of the outline
corresponds to the rotation that the component will undergo following
manipulation. Rotation will be constrained by gravity.
- virtual Graphic* GetGraphic()
- Return the graphic that defines the GraphicView's appearance. Often this
graphic is a copy of that in the subject, but it needn't be.
- virtual Viewer* GetViewer()
- Return the viewer (if any) that displays the view.
- GraphicComp* GetGraphicComp()
- Return the view's subject.
- boolean Includes(GraphicView*)
- A convenience function that returns whether or not the GraphicView
includes the given view, that is, whether the view is a child of
this.
- GraphicView* GetGraphicView(Component*)
- A convenience function that returns the view of the given component (if
any) that appears in the same viewer as this.
- GraphicView* GetView(Iterator)
- void SetView(GraphicView*, Iterator&)
- These operations do nothing by default. Subclasses that contain children
should redefine them as follows: GetView should return the GraphicView to
which an iterator points. SetView should initialize the iterator to point
to a particular GraphicView in the list of children; it should initialize
the iterator to point to a nil instance if the given GraphicView is not a
child.
- virtual Selection* SelectAll()
- virtual Selection* ViewContaining(Coord, Coord)
- virtual Selection* ViewsContaining(Coord, Coord)
- virtual Selection* ViewIntersecting(Coord, Coord, Coord,
Coord)
- virtual Selection* ViewsIntersecting(Coord, Coord, Coord,
Coord)
- virtual Selection* ViewsWithin(Coord, Coord, Coord, Coord)
- virtual ConnectorView* ConnectorIntersecting(
- Coord, Coord, Coord, Coord
- )
-
These convenience operations do nothing by default. Subclasses containing
children should redefine them to do the following: SelectAll should return
a selection object containing (pointers to) all its children;
ViewContaining should return the last (visibly topmost) child view
containing the given point, while ViewsContaining should return all
children containing the point; ViewIntersecting should return the last
(visibly topmost) child view intersecting a rectangular area, while
ViewsIntersecting should return all such children; ViewsWithin should
return all the child views falling strictly within a rectangular area; and
ConnectorIntersecting should return the child ConnectorView (if any) that
intersects a rectangular area.
GRAPHICVIEW PROTECTED OPERATIONS¶
- GraphicView(GraphicComp* = nil)
- The constructor is protected to guard against instantiation. It takes the
view's subject as an optional argument, passing it to the ComponentView
constructor.
- virtual void SetGraphic(Graphic*)
- Set the GraphicView's graphic to the given one, and store this in
the graphic using Graphic::SetTag. This makes it possible to obtain the
GraphicView that owns the graphic from the graphic itself, e.g., after hit
detection.
- virtual void CreateHandles()
- Initialize the _handles member with a rubberband that will draw the
appropriate handles. By default, CreateHandles creates a RubberHandles
object with eight handles around the periphery of the view's bounding
box.
- virtual int ClosestPoint(
- Coord x[], Coord y[], int n, Coord px, Coord py
- )
-
A convenience function that returns the index of the point closest to (
px, py) in an array of n points.
- GraphicView* View(UList*)
- GraphicView* GetGraphicView(Graphic*)
- Convenience functions that return the GraphicView in a UList element and
the GraphicView associated with a graphic, respectively.
- Manipulator* CreateGraphicCompManip(
- Viewer*, Event&, Transformer*, Tool*
- )
- Manipulator* CreateStretchManip(
- Viewer*, Event&, Transformer*, Tool*
- )
- Command* InterpretGraphicCompManip(Manipulator*)
- Command* InterpretStretchManip(Manipulator*)
- Helper functions used by CreateManipulator and InterpretManipulator to
create and interpret the manipulators associated with GraphicCompTool and
StretchTool.
- void AddDamage(Graphic*)
- void IncurDamage(Graphic*)
- GraphicViews should incur damage in response to a change in their
appearance, which generally happens in their Update function. AddDamage
and IncurDamage produce damage by calling the related operations on the
enclosing viewer's damage object. Subclasses can use these functions for
convenience to avoid accessing the enclosing viewer's damage object
directly.
- void Unselect(GraphicView*)
- A convenience function that unselects the given view, which entails
erasing its handles and removing it from the enclosing editor's selection
object.
- virtual void Add(GraphicView*)
- virtual void Append(GraphicView*)
- virtual void InsertBefore(Iterator, GraphicView*)
- virtual void Remove(Iterator&)
- virtual void DeleteView(Iterator&)
- Unimplemented operations that composite subclasses should redefine for
modifying the their (conceptual) list of children. Note that subclasses
needn't necessarily store their children in a list data structure, but a
list maps closely to the semantics of these operations. These operations
are not public because only the view itself knows how to keep its
structure consistent with that of the subject and/or its semantics.
Add adds a GraphicView to the end of the list of children. InsertBefore
inserts a GraphicView before the GraphicView pointed to by the iterator.
Remove removes a view to which the given iterator refers from the list
without deleting it, while DeleteView removes it and deletes it. Remove
and DeleteView should advance the iterator to point to the following view
as a side effect.
GRAPHICVIEWS PUBLIC OPERATIONS¶
- GraphicViews(GraphicComps* = nil)
- virtual ~GraphicViews()
- The constructor creates a GraphicViews, optionally supplying the subject.
The destructor deletes the GraphicViews' children.
- virtual void Interpret(Command*)
- GraphicViews objects interpret the following command:
AlignToGridCmd aligns the graphical component to the grid that
affects the view. The overall alignment is based on how the first leaf
subcomponent aligns itself: Interpret aligns the first leaf subcomponent
to the grid and then moves all other subcomponents by the amount that the
leaf moved.
- virtual void Update()
- Automatically update the GraphicViews' state and structure to match the
subject's. Update will not necessarily detect restructurings or
state modifications made to the subject's children more than one level
deep. Update uses GVUpdater to do its work.
- virtual Graphic* GetGraphic()
- Return the GraphicViews' graphic, which (like its subject's graphic) is a
Picture.
- GraphicComps* GetGraphicComps()
- Return the subject.
GRAPHICVIEWS PROTECTED OPERATIONS¶
- UList* Elem(Iterator)
- A convenience function for extracting a UList from an iterator.
SEE ALSO¶
Command(3U), ComponentView(3U), Connector(3U), Damage(3U), GVUpdater(3U),
GraphicComp(3U), GraphicCompTool(3U), Grid(3U), Event(3I), Manipulator(3U),
MoveTool(3U), Picture(3U), RotateTool(3U), Rubband(3I), ScaleTool(3U),
Selection(3U), StretchTool(3U), Transformer(3I), Viewer(3U), align(3U)