- documentet cairo_widget.hh
git-svn-id: svn://svn.gna.org/svn/sgpemv2/trunk@1143 3ecf2c5c-341e-0410-92b4-d18e462d057c
This commit is contained in:
paolo
parent
9cb356a3f8
commit
c39ecfed50
|
|
@ -30,9 +30,62 @@
|
|||
|
||||
namespace sgpem
|
||||
{
|
||||
/**
|
||||
* \brief Base abstract class to derive widgets that use cairo graphic output.
|
||||
*
|
||||
* This class is the starting point to derive graphics widgets using cairo.
|
||||
* It provides explicit in memory double buffering, and scaling.
|
||||
* In order to build a new widget that uses cairo output the developer should
|
||||
* use this as base class.
|
||||
*
|
||||
* The implementer:
|
||||
* - must
|
||||
* - implement draw_widget() to draw in the widget client area \see draw_widget()
|
||||
* - should
|
||||
* - define calc_drawing_size() to provide correct size calculation
|
||||
* - call resize_redraw() to calc size and redraw
|
||||
* - can
|
||||
* - define calc_widget_size() to get predefined widget dimensions
|
||||
* - set the desired scaling mode \see set_scaling_mode()
|
||||
* - call redraw() to only redraw the widget
|
||||
*
|
||||
*/
|
||||
class CairoWidget : public Gtk::Widget
|
||||
{
|
||||
public:
|
||||
/**
|
||||
* \brief Defines cairo widget scaling modes.
|
||||
*
|
||||
* Scaling is the geometric operation that maps draw_widget()'s output
|
||||
* into client area.
|
||||
* There are some ways to scale the output to fit in client area.
|
||||
* The developer does'n need to know how to build the scaling but
|
||||
* only how it works.
|
||||
* The defined modes are:
|
||||
* - scaling_none without any scaling
|
||||
* - scaling_to_w uses width to calculate scale factor
|
||||
* - scaling_to_h uses height to calculate scale factor
|
||||
* - scaling_min uses minimum scale factor from width, height
|
||||
* - scaling_max uses maximum scale factor from width, height
|
||||
* - scaling_all scale to stretch into client area
|
||||
*
|
||||
* Each mode has advantages and disvantages.
|
||||
* - scaling_none doesn't do any scaling at all.
|
||||
* The graphics are rendered as they are drawn.
|
||||
* - scaling_to_w calc both x and y scaling to fit the client width.
|
||||
* Probably the draw will exceed the client area height.
|
||||
* - scaling_to_h calc both x and y scaling to fit the client height.
|
||||
* Probably the draw will exceed the client area width.
|
||||
* - scaling_min calc both x and y scaling to enter in the client area.
|
||||
* The draw will always fit in the window.
|
||||
* - scaling_max calc both x and y scaling to not enter in the client area.
|
||||
* The draw will rarely fit in the window.
|
||||
* - scaling_all calc x and y scaling to fit exactly in the client area.
|
||||
* The draw will always fit the entire client area.
|
||||
* NOTE: This scaling mode stretch the drawing and not respect the
|
||||
* ratio between width and height.
|
||||
*
|
||||
*/
|
||||
enum scaling_mode
|
||||
{
|
||||
scaling_none = 0, // without any scaling
|
||||
|
|
@ -43,69 +96,195 @@ namespace sgpem
|
|||
scaling_all = 1 << 4 // scale to stretch into client area
|
||||
};
|
||||
|
||||
/**
|
||||
* \brief Unique constructor, initialize data members.
|
||||
*/
|
||||
CairoWidget();
|
||||
|
||||
/**
|
||||
* \brief Widget's destructor.
|
||||
*/
|
||||
virtual ~CairoWidget();
|
||||
|
||||
// scaling related functions
|
||||
/**
|
||||
* \brief Assign the desired scaling mode and returns the old one.
|
||||
*
|
||||
* Change scaling mode; default is scaling_none.
|
||||
* The programmer must call resize_redraw() becous it take effect.
|
||||
*
|
||||
* \param scaling_mode The new desired scaling mode.
|
||||
* \return Previous scaling mode.
|
||||
*/
|
||||
scaling_mode set_scaling_mode(scaling_mode scaling_mode);
|
||||
scaling_mode get_scaling_mode();
|
||||
|
||||
// need for redrawing the widget (double buffering related)
|
||||
/**
|
||||
* \brief Retrieve current scaling mode.
|
||||
*
|
||||
* \return Previous scaling mode.
|
||||
*/
|
||||
scaling_mode get_scaling_mode() const;
|
||||
|
||||
/**
|
||||
* \brief Force the widgets readrawing without calc new size.
|
||||
*
|
||||
* Useful for redrawing the widget (double buffering related).
|
||||
*/
|
||||
void redraw();
|
||||
|
||||
// need for auto resizing and redrawing the widget (double buffering related)
|
||||
/**
|
||||
* \brief Force the widgets readrawing without calc new size.
|
||||
*
|
||||
* Need for auto resizing and redrawing the widget (double buffering related).
|
||||
*/
|
||||
void resize_redraw();
|
||||
|
||||
// TODO - temporary: will be removed soon
|
||||
// void change_scaling_mode();
|
||||
|
||||
protected:
|
||||
/**
|
||||
* \brief Widgets size type.
|
||||
*/
|
||||
typedef unsigned int size_t;
|
||||
|
||||
// implements fundamental widget's method
|
||||
// implementation of fundamental widget's method
|
||||
/**
|
||||
* \brief Implements standard widget's on_realize() mehtod.
|
||||
*
|
||||
* The on_realize() function is called by the Gtk windowing system
|
||||
* before it creates a new widget.
|
||||
* See gtkmm documentation for more informations.
|
||||
*/
|
||||
virtual void on_realize();
|
||||
virtual void on_size_allocate(const Gtk::Allocation& allocation);
|
||||
virtual void on_size_request(Gtk::Requisition* request);
|
||||
virtual bool on_expose_event(GdkEventExpose* event);
|
||||
virtual bool on_button_press_event(GdkEventButton* event);
|
||||
|
||||
// in this method the implemented widget must "do the things"
|
||||
/**
|
||||
* \brief Implements standard widget's on_size_allocate() mehtod.
|
||||
*
|
||||
* The on_size_allocate() function is called by the Gtk windowing system
|
||||
* after creation of a new widget asking the desired widget dimensions.
|
||||
* See gtkmm documentation for more informations.
|
||||
*/
|
||||
virtual void on_size_allocate(const Gtk::Allocation& allocation);
|
||||
|
||||
/**
|
||||
* \brief Implements standard widget's on_size_request() mehtod.
|
||||
*
|
||||
* The on_size_request() function is called by the Gtk windowing system
|
||||
* when need to change the widget dimensions.
|
||||
* See gtkmm documentation for more informations.
|
||||
*/
|
||||
virtual void on_size_request(Gtk::Requisition* request);
|
||||
|
||||
/**
|
||||
* \brief Implements standard widget's on_expose_event() mehtod.
|
||||
*
|
||||
* The on_expose_event() function is called by the Gtk windowing system
|
||||
* when the widgets' redrawing is requested after creation or to update.
|
||||
* See gtkmm documentation for more informations.
|
||||
*/
|
||||
virtual bool on_expose_event(GdkEventExpose* event);
|
||||
/*
|
||||
to delete asap
|
||||
virtual bool on_button_press_event(GdkEventButton* event);
|
||||
*/
|
||||
|
||||
/**
|
||||
* \brief Client area drawing method.
|
||||
*
|
||||
* In this method the implemented widget must "do the things"
|
||||
* and (obviously) its implementation is a need.
|
||||
* The programmer then use the passed cairo context, ctx, to
|
||||
* draw in the widgets client area.
|
||||
* See cairo documentation for more informations.
|
||||
*/
|
||||
virtual void draw_widget(cairo_t* ctx) = 0;
|
||||
|
||||
// with this method CairoWidget tells the needed drawing dimensions
|
||||
/**
|
||||
* \brief Method to calculate widget dimensions.
|
||||
*
|
||||
* The user should implement this method to allow scaling factors calculation.
|
||||
* Is necessary if scaling is needed/used.
|
||||
*/
|
||||
virtual void calc_drawing_size(cairo_t* ctx, size_t& width, size_t& height);
|
||||
|
||||
// with this method CairoWidget tells the needed widgwt dimensions
|
||||
// with this method CairoWidget tells the needed widget dimensions
|
||||
/**
|
||||
* \brief Method to define default widget dimensions.
|
||||
*
|
||||
* The user can implement this method to give default dimensions.
|
||||
* It isn't necessary because scaling (and resizing) take care of calc_drawing_size() results.
|
||||
*/
|
||||
virtual void calc_widget_size(size_t& width, size_t& height);
|
||||
|
||||
/**
|
||||
* \brief Calculate scaling factors to apply during widget's redrawing.
|
||||
*
|
||||
* This method is used internally to recomute scaling factors.
|
||||
* Implementors of derived calsses doesn't worry about it.
|
||||
*/
|
||||
void calc_scale_factors();
|
||||
|
||||
/*
|
||||
I don't know the meaning of these definition!
|
||||
Paolo
|
||||
typedef Gdk::Rectangle area_t;
|
||||
typedef sigc::mem_functor0<void, CairoWidget> method0_t;
|
||||
typedef std::pair<area_t, method0_t> area_callback_t;
|
||||
typedef std::vector<area_callback_t> areas_vect_t;
|
||||
*/
|
||||
|
||||
/**
|
||||
* \brief Calculated width of drawing.
|
||||
*;
|
||||
mutable size_t _draw_w;
|
||||
|
||||
/**
|
||||
* \brief Calculated height of drawing.
|
||||
*;
|
||||
mutable size_t _draw_h;
|
||||
|
||||
private:
|
||||
// The width and height the widget will assume, must be determined
|
||||
// before starting drawing by calc_size()
|
||||
// drawing dimensions required
|
||||
// window client area
|
||||
/**
|
||||
* \brief Client area width of widget.
|
||||
*/
|
||||
mutable size_t _client_w;
|
||||
|
||||
/**
|
||||
* \brief Client area height of widget.
|
||||
*/
|
||||
mutable size_t _client_h;
|
||||
// pixmap client area
|
||||
|
||||
/**
|
||||
* \brief Client area width of pixmap.
|
||||
*/
|
||||
mutable size_t _pixmap_w;
|
||||
|
||||
/**
|
||||
* \brief Client area width of pixmap.
|
||||
*/
|
||||
mutable size_t _pixmap_h;
|
||||
// cairo scale factors
|
||||
|
||||
/**
|
||||
* \brief Cairo x scale factor.
|
||||
*/
|
||||
mutable double _scale_x;
|
||||
|
||||
/**
|
||||
* \brief Cairo y scale factor.
|
||||
*/
|
||||
mutable double _scale_y;
|
||||
|
||||
/**
|
||||
* \brief Flag to signal require redrawing.
|
||||
*/
|
||||
mutable bool _need_redraw;
|
||||
|
||||
/**
|
||||
* \brief Actual scaling mode.
|
||||
*/
|
||||
scaling_mode _scaling_mode;
|
||||
|
||||
// The offscreen pixmap we use for double-buffering
|
||||
/**
|
||||
* \brief Offscreen pixmap used for double-buffering.
|
||||
*/
|
||||
Glib::RefPtr<Gdk::Pixmap> _buf;
|
||||
};
|
||||
|
||||
|
|
|
|||
Loading…
Reference in New Issue