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+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Authors:
+ * Krzysztof KosiƄski <tweenk.pl@gmail.com>
+ * Jon A. Cruz <jon@joncruz.org>
+ *
+ * Copyright (C) 2012 Authors
+ * Copyright (C) 2009 Authors
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#ifndef SEEN_UI_TOOL_CONTROL_POINT_H
+#define SEEN_UI_TOOL_CONTROL_POINT_H
+
+#include <gdkmm/pixbuf.h>
+#include <boost/utility.hpp>
+#include <cstddef>
+#include <sigc++/signal.h>
+#include <sigc++/trackable.h>
+#include <2geom/point.h>
+
+// #include "ui/control-types.h"
+#include "display/control/canvas-item-ctrl.h"
+#include "display/control/canvas-item-enums.h"
+
+#include "enums.h" // TEMP TEMP
+
+class SPDesktop;
+
+namespace Inkscape {
+namespace UI {
+namespace Tools {
+
+class ToolBase;
+
+}
+}
+}
+
+namespace Inkscape {
+namespace UI {
+
+/**
+ * Draggable point, the workhorse of on-canvas editing.
+ *
+ * Control points (formerly known as knots) are graphical representations of some significant
+ * point in the drawing. The drawing can be changed by dragging the point and the things that are
+ * attached to it with the mouse. Example things that could be edited with draggable points
+ * are gradient stops, the place where text is attached to a path, text kerns, nodes and handles
+ * in a path, and many more.
+ *
+ * @par Control point event handlers
+ * @par
+ * The control point has several virtual methods which allow you to react to things that
+ * happen to it. The most important ones are the grabbed, dragged, ungrabbed and moved functions.
+ * When a drag happens, the order of calls is as follows:
+ * - <tt>grabbed()</tt>
+ * - <tt>dragged()</tt>
+ * - <tt>dragged()</tt>
+ * - <tt>dragged()</tt>
+ * - ...
+ * - <tt>dragged()</tt>
+ * - <tt>ungrabbed()</tt>
+ *
+ * The control point can also respond to clicks and double clicks. On a double click,
+ * clicked() is called, followed by doubleclicked(). When deriving from SelectableControlPoint,
+ * you need to manually call the superclass version at the appropriate point in your handler.
+ *
+ * @par Which method to override?
+ * @par
+ * You might wonder which hook to use when you want to do things when the point is relocated.
+ * Here are some tips:
+ * - If the point is used to edit an object, override the move() method.
+ * - If the point can usually be dragged wherever you like but can optionally be constrained
+ * to axes or the like, add a handler for <tt>signal_dragged</tt> that modifies its new
+ * position argument.
+ * - If the point has additional canvas items tied to it (like handle lines), override
+ * the setPosition() method.
+ */
+class ControlPoint : boost::noncopyable, public sigc::trackable {
+public:
+
+ /**
+ * Enumeration representing the possible states of the control point, used to determine
+ * its appearance.
+ *
+ * @todo resolve this to be in sync with the five standard GTK states.
+ */
+ enum State {
+ /** Normal state. */
+ STATE_NORMAL,
+
+ /** Mouse is hovering over the control point. */
+ STATE_MOUSEOVER,
+
+ /** First mouse button pressed over the control point. */
+ STATE_CLICKED
+ };
+
+ /**
+ * Destructor
+ */
+ virtual ~ControlPoint();
+
+ /// @name Adjust the position of the control point
+ /// @{
+ /** Current position of the control point. */
+ Geom::Point const &position() const { return _position; }
+
+ operator Geom::Point const &() { return _position; }
+
+ /**
+ * Move the control point to new position with side effects.
+ * This is called after each drag. Override this method if only some positions make sense
+ * for a control point (like a point that must always be on a path and can't modify it),
+ * or when moving a control point changes the positions of other points.
+ */
+ virtual void move(Geom::Point const &pos);
+
+ /**
+ * Relocate the control point without side effects.
+ * Overload this method only if there is an additional graphical representation
+ * that must be updated (like the lines that connect handles to nodes). If you override it,
+ * you must also call the superclass implementation of the method.
+ * @todo Investigate whether this method should be protected
+ */
+ virtual void setPosition(Geom::Point const &pos);
+
+ /**
+ * Apply an arbitrary affine transformation to a control point. This is used
+ * by ControlPointSelection, and is important for things like nodes with handles.
+ * The default implementation simply moves the point according to the transform.
+ */
+ virtual void transform(Geom::Affine const &m);
+
+ /**
+ * Apply any node repairs, by default no fixing is applied but Nodes will update
+ * smooth nodes to make sure nodes are kept consistent.
+ */
+ virtual void fixNeighbors() {};
+
+ /// @}
+
+ /// @name Toggle the point's visibility
+ /// @{
+ bool visible() const;
+
+ /**
+ * Set the visibility of the control point. An invisible point is not drawn on the canvas
+ * and cannot receive any events. If you want to have an invisible point that can respond
+ * to events, use <tt>invisible_cset</tt> as its color set.
+ */
+ virtual void setVisible(bool v);
+ /// @}
+
+ /// @name Transfer grab from another event handler
+ /// @{
+ /**
+ * Transfer the grab to another point. This method allows one to create a draggable point
+ * that should be dragged instead of the one that received the grabbed signal.
+ * This is used to implement dragging out handles in the new node tool, for example.
+ *
+ * This method will NOT emit the ungrab signal of @c prev_point, because this would complicate
+ * using it with selectable control points. If you use this method while dragging, you must emit
+ * the ungrab signal yourself.
+ *
+ * Note that this will break horribly if you try to transfer grab between points in different
+ * desktops, which doesn't make much sense anyway.
+ */
+ void transferGrab(ControlPoint *from, GdkEventMotion *event);
+ /// @}
+
+ /// @name Inspect the state of the control point
+ /// @{
+ State state() const { return _state; }
+
+ bool mouseovered() const { return this == mouseovered_point; }
+ /// @}
+
+ /** Holds the currently mouseovered control point. */
+ static ControlPoint *mouseovered_point;
+
+ /**
+ * Emitted when the mouseovered point changes. The parameter is the new mouseovered point.
+ * When a point ceases to be mouseovered, the parameter will be NULL.
+ */
+ static sigc::signal<void, ControlPoint*> signal_mouseover_change;
+
+ static Glib::ustring format_tip(char const *format, ...) G_GNUC_PRINTF(1,2);
+
+ // temporarily public, until snap delay is refactored a little
+ virtual bool _eventHandler(Inkscape::UI::Tools::ToolBase *event_context, GdkEvent *event);
+ SPDesktop *const _desktop; ///< The desktop this control point resides on.
+
+ bool doubleClicked() {return _double_clicked;}
+
+protected:
+
+ struct ColorEntry {
+ guint32 fill;
+ guint32 stroke;
+ };
+
+ /**
+ * Color entries for each possible state.
+ * @todo resolve this to be in sync with the five standard GTK states.
+ */
+ struct ColorSet {
+ ColorEntry normal;
+ ColorEntry mouseover;
+ ColorEntry clicked;
+ ColorEntry selected_normal;
+ ColorEntry selected_mouseover;
+ ColorEntry selected_clicked;
+ };
+
+ /**
+ * A color set which you can use to create an invisible control that can still receive events.
+ */
+ static ColorSet invisible_cset;
+
+ /**
+ * Create a regular control point.
+ * Derive to have constructors with a reasonable number of parameters.
+ *
+ * @param d Desktop for this control
+ * @param initial_pos Initial position of the control point in desktop coordinates
+ * @param anchor Where is the control point rendered relative to its desktop coordinates
+ * @param type Logical type of the control point.
+ * @param cset Colors of the point
+ * @param group The canvas group the point's canvas item should be created in
+ */
+ ControlPoint(SPDesktop *d, Geom::Point const &initial_pos, SPAnchorType anchor,
+ Inkscape::CanvasItemCtrlType type,
+ ColorSet const &cset = _default_color_set,
+ Inkscape::CanvasItemGroup *group = nullptr);
+
+ /**
+ * Create a control point with a pixbuf-based visual representation.
+ *
+ * @param d Desktop for this control
+ * @param initial_pos Initial position of the control point in desktop coordinates
+ * @param anchor Where is the control point rendered relative to its desktop coordinates
+ * @param pixbuf Pixbuf to be used as the visual representation
+ * @param cset Colors of the point
+ * @param group The canvas group the point's canvas item should be created in
+ */
+ ControlPoint(SPDesktop *d, Geom::Point const &initial_pos, SPAnchorType anchor,
+ Glib::RefPtr<Gdk::Pixbuf> pixbuf,
+ ColorSet const &cset = _default_color_set,
+ Inkscape::CanvasItemGroup *group = nullptr);
+
+ /// @name Handle control point events in subclasses
+ /// @{
+ /**
+ * Called when the user moves the point beyond the drag tolerance with the first button held
+ * down.
+ *
+ * @param event Motion event when drag tolerance was exceeded.
+ * @return true if you called transferGrab() during this method.
+ */
+ virtual bool grabbed(GdkEventMotion *event);
+
+ /**
+ * Called while dragging, but before moving the knot to new position.
+ *
+ * @param pos Old position, always equal to position()
+ * @param new_pos New position (after drag). This is passed as a non-const reference,
+ * so you can change it from the handler - that's how constrained dragging is implemented.
+ * @param event Motion event.
+ */
+ virtual void dragged(Geom::Point &new_pos, GdkEventMotion *event);
+
+ /**
+ * Called when the control point finishes a drag.
+ *
+ * @param event Button release event
+ */
+ virtual void ungrabbed(GdkEventButton *event);
+
+ /**
+ * Called when the control point is clicked, at mouse button release.
+ * Improperly implementing this method can cause the default context menu not to appear when a control
+ * point is right-clicked.
+ *
+ * @param event Button release event
+ * @return true if the click had some effect, false if it did nothing.
+ */
+ virtual bool clicked(GdkEventButton *event);
+
+ /**
+ * Called when the control point is doubleclicked, at mouse button release.
+ *
+ * @param event Button release event
+ */
+ virtual bool doubleclicked(GdkEventButton *event);
+ /// @}
+
+ /// @name Manipulate the control point's appearance in subclasses
+ /// @{
+
+ /**
+ * Change the state of the knot.
+ * Alters the appearance of the knot to match one of the states: normal, mouseover
+ * or clicked.
+ */
+ virtual void _setState(State state);
+
+ void _handleControlStyling();
+
+ void _setColors(ColorEntry c);
+
+ void _setSize(unsigned int size);
+
+ void _setControlType(Inkscape::CanvasItemCtrlType type);
+
+ void _setAnchor(SPAnchorType anchor);
+
+ void _setPixbuf(Glib::RefPtr<Gdk::Pixbuf>);
+
+ /**
+ * Determines if the control point is not visible yet still reacting to events.
+ *
+ * @return true if non-visible, false otherwise.
+ */
+ bool _isLurking();
+
+ /**
+ * Sets the control point to be non-visible yet still reacting to events.
+ *
+ * @param lurking true to make non-visible, false otherwise.
+ */
+ void _setLurking(bool lurking);
+
+ /// @}
+
+ virtual Glib::ustring _getTip(unsigned /*state*/) const { return ""; }
+
+ virtual Glib::ustring _getDragTip(GdkEventMotion */*event*/) const { return ""; }
+
+ virtual bool _hasDragTips() const { return false; }
+
+
+ Inkscape::CanvasItemCtrl * _canvas_item_ctrl = nullptr; ///< Visual representation of the control point.
+
+ ColorSet const &_cset; ///< Colors used to represent the point
+
+ State _state = STATE_NORMAL;
+
+ static Geom::Point const &_last_click_event_point() { return _drag_event_origin; }
+
+ static Geom::Point const &_last_drag_origin() { return _drag_origin; }
+
+ static bool _is_drag_cancelled(GdkEventMotion *event);
+
+ /** Events which should be captured when a handle is being dragged. */
+ static Gdk::EventMask const _grab_event_mask;
+
+ static bool _drag_initiated;
+
+private:
+
+ ControlPoint(ControlPoint const &other);
+
+ void operator=(ControlPoint const &other);
+
+ static bool _event_handler(GdkEvent *event, ControlPoint *point);
+
+ static void _setMouseover(ControlPoint *, unsigned state);
+
+ static void _clearMouseover();
+
+ bool _updateTip(unsigned state);
+
+ bool _updateDragTip(GdkEventMotion *event);
+
+ void _setDefaultColors();
+
+ void _commonInit();
+
+ Geom::Point _position; ///< Current position in desktop coordinates
+
+ sigc::connection _event_handler_connection;
+
+ bool _lurking = false;
+
+ static ColorSet _default_color_set;
+
+ /** Stores the window point over which the cursor was during the last mouse button press. */
+ static Geom::Point _drag_event_origin;
+
+ /** Stores the desktop point from which the last drag was initiated. */
+ static Geom::Point _drag_origin;
+
+ static bool _event_grab;
+
+ bool _double_clicked = false;
+};
+
+
+} // namespace UI
+} // namespace Inkscape
+
+#endif
+
+/*
+ Local Variables:
+ mode:c++
+ c-file-style:"stroustrup"
+ c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+ indent-tabs-mode:nil
+ fill-column:99
+ End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :