lumiera_/src/gui/widgets/timeline/timeline-layout-helper.hpp
2009-01-24 10:58:54 +00:00

421 lines
12 KiB
C++

/*
timeline-layout-helper.hpp - Declaration of the timeline
layout helper class
Copyright (C) Lumiera.org
2008, Joel Holdsworth <joel@airwebreathe.org.uk>
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/** @file timeline-layout-helper.cpp
** This file contains the definition of the layout helpeer class
*/
#ifndef TIMELINE_LAYOUT_HELPER_HPP
#define TIMELINE_LAYOUT_HELPER_HPP
#include "../../gtk-lumiera.hpp"
#include "../../../lib/tree.hpp"
namespace gui {
namespace model {
class Track;
}
namespace widgets {
class TimelineWidget;
namespace timeline {
class Track;
/**
* A helper class for the TimelineWidget. TimelineLayoutHelper
* is a class which calculates the layout of tracks in the timeline
* track tree.
* @see gui::widgets::TimelineWidget
*/
class TimelineLayoutHelper : public boost::noncopyable
{
public:
/**
* Definition of the layout track tree type.
**/
typedef lumiera::tree< boost::shared_ptr<model::Track> > TrackTree;
public:
/**
* Constructor.
* @param owner The timeline widget which is the owner of this helper
* class.
**/
TimelineLayoutHelper(TimelineWidget &owner);
/**
* Clones the timelineWidget sequence's track tree to create a layout
* tree which will be identitcal to it.
* @remarks The current layout tree will be deleted and replaced with
* the clone.
* @see add_branch
**/
void clone_tree_from_sequence();
/**
* Gets a reference to the helper's layout tree.
* @return Returns a reference to the helper's layout tree.
**/
TrackTree& get_layout_tree();
/**
* Recalculates the track layout from layoutTree.
* @see layout_headers_recursive
**/
void update_layout();
/**
* Get's the header rectangle of a given timeline track.
* @param[in] track The track which will be looked up.
* @return Returns the rectangle of the header offset by the y-scroll
* offset, or if the track is hidden, or not present in the layout
* tree, an empty optional will be returned.
* @remarks This function is only usable after update_layout() has
* been called on a valid tree of tracks.
* @see update_layout()
**/
boost::optional<Gdk::Rectangle> get_track_header_rect(
boost::weak_ptr<timeline::Track> track);
/**
* Searches for a header which has the specified point inside of it.
* @param[in] point The point to search with.
* @return Returns the header which has been found, or if no header is
* found, an empty shared pointer is returned.
* @remarks The point specified is relative to the scroll offset, so
* y = 0 is the top edge of the scroll view. This function is only
* usable after update_layout() has been called on a valid tree of
* tracks.
* @see update_layout()
**/
boost::shared_ptr<timeline::Track> header_from_point(
Gdk::Point point);
/**
* Searches for a tack which has the specified y-offset inside of it.
* @param[in] y The y-coordinate to search with.
* @return Returns the track which has been found, or if no track is
* found, an empty shared pointer is returned.
* @remarks The point specified is relative to the scroll offset, so
* y = 0 is the top edge of the scroll view. This function is only
* usable after update_layout() has been called on a valid tree of
* tracks.
* @see update_layout()
**/
boost::shared_ptr<timeline::Track> track_from_y(int y);
/**
* Begins to drag the track under mouse_point, if there is one.
* @param mouse_point The mouse point to begin dragging from, measured
* in pixels from the top left of the header container widget.
**/
boost::shared_ptr<timeline::Track>
begin_dragging_track(const Gdk::Point &mouse_point);
/**
* Drops the dragging track.
* @param apply true if the model tree should be modified.
**/
void end_dragging_track(bool apply);
/**
* Returns true if a track is being dragged.
**/
bool is_dragging_track() const;
/**
* Gets the iterator of the layout tree node that is being dragged.
**/
TrackTree::pre_order_iterator get_dragging_track_iter() const;
/**
* Drags the dragging branch to a new mouse point.
* @param mouse_point The mouse point to drag the dragging track to.
* This point is in pixels relative to the top left of the header
* container.
* @remarks drag_to_point may only be called after
* begin_dragging_track and before end_dragging_point have been
* called.
**/
void drag_to_point(const Gdk::Point &mouse_point);
/**
* Returns the total height in pixels of the layout tree.
* @remarks This function is only on returns a valid value fter
* update_layout() has been called on a valid tree of tracks.
* @see update_layout()
**/
int get_total_height() const;
/**
* Returns true if the layout is currently animating.
**/
bool is_animating() const;
/**
* A utility function which finds the iterator of a track in the
* layout tree.
* @param model_track The model track to look for.
* @return Returns the model iterator of layoutTree.end() if no
* iterator was found.
**/
TrackTree::pre_order_iterator iterator_from_track(
boost::shared_ptr<model::Track> model_track);
/**
* A function that recursively calculates the visible height of a
* branch taking into account branches that are expanded or collapsed.
* @param parent_iterator The parent of the branch to measure. This
* node and all the child nodes will be included in the measurement.
* @return Returns the height of the branch in pixels.
**/
int measure_branch_height(TrackTree::iterator_base parent_iterator);
protected:
/**
* An enum to specify the relationship between a tree node, and
* another node which is going to be inserted adjacent.
**/
enum TreeRelation
{
/**
* No relation
**/
None,
/**
* The node will be inserted immediately before this one.
**/
Before,
/**
* The node will be inserted immediately after this one.
**/
After,
/**
* The node will be inserted as the first child of this one.
**/
FirstChild,
/**
* The node will be inserted as the last child of this one.
**/
LastChild
};
/**
* A structure used to specify where a track will be dropped when
* dragging ends.
**/
struct DropPoint
{
/**
* Specifies the target node onto which the dragging track will be
* dropped.
**/
TrackTree::pre_order_iterator target;
/**
* The where to drop the dragging track in relation to target.
**/
TreeRelation relation;
};
protected:
/**
* A helper function for clone_tree_from_sequence(). This function
* clones a branch within the model tree into the specified point in
* that layout tree.
* @param[in] parent_iterator The iterator of the node in the tree
* which will become the parent of any tracks added.
* @param[in] parent A pointer to the model track whose children
* will be added to the layout tree branch.
* @see clone_tree_from_sequence()
**/
void add_branch(TrackTree::iterator_base parent_iterator,
boost::shared_ptr<model::Track> parent);
/**
* Recursively calculates the boxes for a given branch in the timeline
* tree.
* @param[in] parent_iterator The iterator of the parent of the branch
* whose boxes will be laid out.
* @param[in] branch_offset The y-coordinate of the start of this
* branch as measured in pixels from the origin.
* @param[in] header_width The width of the header container widget in
* pixels.
* @param[in] header_width The width of indentation per branch in
* pixels.
* @param[in] depth The depth within the tree of tracks. depth = 0 for
* root tracks.
* @param[in] parent_expanded This value is set to true if all of the
* ancestors of this track, up to the root are expanded and visible,
* false if any of them are collapsed.
* @return Returns the height of the branch in pixels.
* @see update_layout()
**/
int layout_headers_recursive(
TrackTree::iterator_base parent_iterator, const int branch_offset,
const int header_width, const int indent_width, const int depth,
const bool parent_expanded);
/**
* A helper function which calls lookup_timeline_track within the
* parent timeline widget, but also applies lots of data consistency
* checks in the process.
* @param model_track The model track to look up in the parent widget.
* @return Returns the track found, or returns NULL if no matching
* track was found.
* @remarks If the return value is going to be NULL, an ENSURE will
* fail.
**/
boost::shared_ptr<timeline::Track> lookup_timeline_track(
boost::shared_ptr<model::Track> model_track);
/**
* A helper function which kicks off the animation timer.
**/
void begin_animation();
/**
* The animation timer tick callback.
**/
bool on_animation_tick();
/**
* Attempts to find a drop point on the target node at point.
* @param[in] target The iterator of the target node on which to make
* the attempt.
* @param[in] point The point on which do to the test.
* @remarks This function hit-tests a header looking to see if the
* point is hovering over it, and if it is, it works out what part of
* the header, and therefore what drop location the user us gesturally
* pointing to.
**/
TimelineLayoutHelper::DropPoint
attempt_drop(TrackTree::pre_order_iterator target,
const Gdk::Point &point);
/**
* Drops the dragging track to a new location in the layout tree as
* specified by drop.
* @param[in] drop The point in the tree to drop onto.
**/
void apply_drop_to_layout_tree(const DropPoint &drop);
/**
* Drops the dragging track to a new location in the model tree as
* specified by drop.
* @param[in] drop The point in the tree to drop onto.
**/
void apply_drop_to_model_tree(const DropPoint &drop);
protected:
/**
* The owner timeline widget as provided to the constructor.
**/
TimelineWidget &timelineWidget;
/**
* The layout tree.
**/
TrackTree layoutTree;
/**
* A map of tracks to the rectangles of their headers.
* @remarks This map is used as a cache, so that the rectangles don't
* need to be perpetually recalculated. This cache is regenerated by
* the update_layout method.
* @see update_layout()
**/
std::map<boost::weak_ptr<timeline::Track>, Gdk::Rectangle>
headerBoxes;
/**
* The total height of the track tree layout in pixels. This value
* is only valid after layout_headers has been called.
* @see update_layout()
**/
int totalHeight;
/**
* The iterator of the layoutTree node that is presently being
* dragged.
* @remarks draggingTrackIter.node is set to NULL when no drag is
* taking place.
**/
TrackTree::pre_order_iterator draggingTrackIter;
/**
* The offset of the mouse relative to the top-left corner of the
* dragging track.
**/
Gdk::Point dragStartOffset;
/**
* The coordinates of the dragging mouse in pixels, measured from the
* top left of the whole layout.
* @remarks This value is changed by begin_dragging_track and
* drag_to_point
**/
Gdk::Point dragPoint;
/**
* The total height of the dragging branch in pixels.
* @remarks This value is updated by begin_dragging_track
**/
int dragBranchHeight;
/**
* The tree point the the user is currently hovering on.
* @remarks This value is updated by drag_to_point.
**/
DropPoint dropPoint;
/**
* The connection to the animation timer.
* @see begin_animation()
* @see on_animation_tick()
**/
sigc::connection animationTimer;
/**
* This value is true if the layout animation should continue.
* @remarks This value is recalculated by update_layout()
* @see update_layout()
* @see on_animation_tick()
**/
bool animating;
};
} // namespace timeline
} // namespace widgets
} // namespace gui
#endif // TIMELINE_LAYOUT_HELPER_HPP