Index

Package: Style

Description

package Gtkada.Style is
Utility functions that mimic Gtk.Style drawing methods, but using Cairo instead of Gdk. This allow smooth transition to Gtk3 that will get rid of those Gdk drawing methods and only use Cairo.

Types

Cairo_Color_Val 

subtype Cairo_Color_Val is Glib.Gdouble range 0.0 .. 1.0;
In cairo, the color components are expressed as percents.

Cairo_Color 

subtype Cairo_Color is Gdk.RGBA.Gdk_RGBA;

HSV_Color 

type HSV_Color is record
      H, S, V, A : Glib.Gdouble;
   end record;
Used when manipulating Cairo color. The HSV color space is useful when wanting to shade a color (change it's value), (de)saturate it, or modify its hue.

HSLA_Color 

type HSLA_Color is record
      Hue        : Glib.Gdouble;
      Saturation : Glib.Gdouble;
      Lightness  : Glib.Gdouble;
      Alpha      : Glib.Gdouble;
   end record;
The Hue is the colour's position on the colour wheel, expressed in degrees from 0° to 359°, representing the 360° of the wheel; 0° being red, 180° being red's opposite colour cyan, and so on. The mapping is: 0.0 => 0° 1.0 => 360° Saturation is the intensity of the colour, how dull or bright it is. The lower the saturation, the duller (greyer) the colour looks. This is expressed as a percentage, 100% being full saturation, the brightest, and 0% being no saturation, grey. Lightness is how light the colour is. Slightly different to saturation. The more white in the colour the higher its Lightness value, the more black, the lower its Lightness. So 100% Lightness turns the colour white, 0% Lightness turns the colour black, and the "pure" colour would be 50% Lightness.

Percent 

subtype Percent is Glib.Gdouble range 0.0 .. 1.0;

Subprograms & Entries

To_HSLA 

function To_HSLA 
(Color: Gdk.RGBA.Gdk_RGBA) return HSLA_Color;

To_RGBA 

function To_RGBA 
(Color: HSLA_Color) return Gdk.RGBA.Gdk_RGBA;

To_HSV 

function To_HSV 
(Color: Cairo_Color) return HSV_Color;

To_Cairo 

function To_Cairo 
(Color: Cairo_Color) return Gdk.RGBA.Gdk_RGBA;

To_Cairo 

function To_Cairo 
(HSV: HSV_Color) return Cairo_Color;

To_Cairo 

function To_Cairo 
(Color: Gdk.Color.Gdk_Color) return Cairo_Color;
Translations between one color definition to another

Set_Source_Color 

procedure Set_Source_Color 
(Cr: Cairo.Cairo_Context;
Color: Cairo_Color);

To_Hex 

function To_Hex 
(Color: Gdk.RGBA.Gdk_RGBA) return String;
Return a hexadecimal approximate representation of the color, of the form "#rrggbb". This loses the alpha chanel. The output is suitable for use in a markup (see Gtk.Label.Set_Markup for instance)

Complementary 

function Complementary 
(Color: Gdk.RGBA.Gdk_RGBA) return Gdk.RGBA.Gdk_RGBA;
Return the complementary color

Shade 

function Shade 
(Color: Gdk.Color.Gdk_Color;
Value: Percent) return Cairo_Color;

Shade 

function Shade 
(Color: Cairo_Color;
Value: Percent) return Cairo_Color;
Modifies the lightning of the color by the specified value. Value is a modifier: 0.0 means the color is unchanged, 0.1 means the color is modified by 10%, and so on.

Lighten 

function Lighten 
(Color: Gdk.RGBA.Gdk_RGBA;
Amount: Percent) return Gdk.RGBA.Gdk_RGBA;
Return a lighter version of the color Amount is a modifier: 0.0 means the color is unchanged, 0.1 means the color is modified by 10%, and so on.

Shade_Or_Lighten 

function Shade_Or_Lighten 
(Color: Gdk.RGBA.Gdk_RGBA;
Amount: Percent := 0.4) return Gdk.RGBA.Gdk_RGBA;
Return a lighter or darker version of Color, depending on whether color is rather dark or rather light. Amount is a modifier: 0.0 means the color is unchanged, 0.1 means the color is modified by 10%, and so on.

Rounded_Rectangle 

procedure Rounded_Rectangle 
(Cr: Cairo.Cairo_Context;
X, Y, W, H: Glib.Gdouble;
Radius: Glib.Gdouble);
Draws a rounded rectangle at coordinate X, Y with W and H size. If Radius > 0, then the corner will be rounded.

Draw_Shadow 

procedure Draw_Shadow 
(Cr: Cairo.Cairo_Context;
Widget: not null access Gtk.Widget.Gtk_Widget_Record'Class;
Shadow_Type: Gtk.Enums.Gtk_Shadow_Type;
X, Y, Width, Height: Glib.Gint;
Corner_Radius: Glib.Gdouble := 0.0);
Draws a Frame of size Width x Height at position (X, Y) and (X2, Y2) using the specified color. Corner_Radius allows you to draw a rounded frame if set to a value > 0. Additional drawing styles can be specified by using Cairo.Set_Line_XXXX on the Cairo_Context before calling this procedure.

Draw_Rectangle 

procedure Draw_Rectangle 
(Cr: Cairo.Cairo_Context;
Color: Cairo_Color;
Filled: Boolean;
X, Y, Width, Height: Glib.Gint;
Corner_Radius: Glib.Gdouble := 0.0);

Draw_Rectangle 

procedure Draw_Rectangle 
(Cr: Cairo.Cairo_Context;
Color: Gdk.Color.Gdk_Color;
Filled: Boolean;
X, Y, Width, Height: Glib.Gint;
Corner_Radius: Glib.Gdouble := 0.0);
Draws a rectangle of size Width x Height at position (X, Y) and (X2, Y2) using the specified color. Corner_Radius allows you to draw a rounded rectangle if set to a value > 0.0 Additional drawing styles can be specified by using Cairo.Set_Line_XXXX on the Cairo_Context before calling this procedure.

Draw_Line 

procedure Draw_Line 
(Cr: Cairo.Cairo_Context;
Color: Cairo_Color;
X1, Y1, X2, Y2: Glib.Gint);

Draw_Line 

procedure Draw_Line 
(Cr: Cairo.Cairo_Context;
Color: Gdk.Color.Gdk_Color;
X1, Y1, X2, Y2: Glib.Gint);
Draws a line between (X1, Y1) and (X2, Y2) using the specified color. Additional drawing styles can be specified by using Cairo.Set_Line_XXXX on the Cairo_Context before calling this procedure.

Draw_Layout 

procedure Draw_Layout 
(Cr: Cairo.Cairo_Context;
Color: Cairo_Color;
X, Y: Glib.Gint;
Layout: Pango.Layout.Pango_Layout);

Draw_Layout 

procedure Draw_Layout 
(Cr: Cairo.Cairo_Context;
Color: Gdk.Color.Gdk_Color;
X, Y: Glib.Gint;
Layout: Pango.Layout.Pango_Layout);
Draws the Pango layout at position (X, Y) using Color.

Draw_Pixbuf 

procedure Draw_Pixbuf 
(Cr: Cairo.Cairo_Context;
Pixbuf: Gdk.Pixbuf.Gdk_Pixbuf;
X, Y: Glib.Gint);
Draws a pixbuf at coordinate X, Y Note that Gdk_Pixmap or Gdk_Bitmap are not supported, as those are server-side images, so depend on a surface attached to a screen. As a result, those would not be drawn on a non-screen surface (such as an internal Image_Surface).

Load_Css_File 

procedure Load_Css_File 
(Path: String;
Error: access procedure (Str : String) := null;
Priority: Gtk.Style_Provider.Priority);

Load_Css_String 

procedure Load_Css_String 
(Data: String;
Error: access procedure (Str : String) := null;
Priority: Gtk.Style_Provider.Priority);
Load CSS file and register it as a default CSS provider for the whole application. In case of error, the procedure Error is called if defined.

Snapshot 

function Snapshot 
(Widget: not null access Gtk.Widget.Gtk_Widget_Record'Class) return Cairo.Cairo_Surface;
Create a snapshot of the widget. This allocates a new surface and draws the widget on it. The surface needs to be destroyed when you are done with it using Surface_Destroy. The snapshot can be drawn on another surface using Set_Source_Surface (Cr, the_snapshot, 0.0, 0.0); Set_Operator (Cr, Cairo_Operator_Source); Rectangle (Cr, ....); Cairo.Fill (Cr); The 0.0 values might need to be adjusted if your widget does not have its own window. In this case, you should use: Get_Allocation (Widget, Alloc); -- and replace 0.0 with Gdouble (Alloc.X)

Draw_Overlay 

procedure Draw_Overlay 
(Widget: not null access Gtk.Widget.Gtk_Widget_Record'Class;
Overlay: in out Cairo.Cairo_Surface;
Do_Draw: not null access procedure (Context : Cairo.Cairo_Context;
Draw: Boolean));
Create an overlay on top of widget on which you can draw. This overlay is created if it doesn't exist (so Overlay must be initialied to Null_Surface initially). It is displayed on top of the toplevel window that contains Widget, and will be fully visible until some of the children of that toplevel window get a "draw" event. At that point, the children will partially override the overlay. This is not a problem in practice if the overlay is displayed while performing operations like a drag-and-drop. Do_Draw is the callback used to do the actual drawing or erasing of the overlay (depending on whether Draw is True or False). The context passed in argument has been properly translated and clipped so that (0, 0) are the coordinates of the top-left corner of widget. When Draw is False, the procedure should display a filled rectangle. The context has already been set up so that filling will in fact redraw what was previously hidden. This is more efficient that having Draw_Overlay systematically fill the whole area.

Delete_Overlay 

procedure Delete_Overlay 
(Widget: not null access Gtk.Widget.Gtk_Widget_Record'Class;
Overlay: in out Cairo.Cairo_Surface);
Delete the overlay created by Draw_Overlay, and force a refresh of the toplevel window.

Get_Offset 

procedure Get_Offset 
(Window: not null access Gtk.Widget.Gtk_Widget_Record'Class;
Parent: not null access Gtk.Widget.Gtk_Widget_Record'Class;
X, Y: out Glib.Gint);
Get the position of Window within parent's window (not that this is not necessarily the same as the position within Parent if the latter does not have a window).

Get_First_Device 

function Get_First_Device 
(Widget: not null access Gtk.Widget.Gtk_Widget_Record'Class;
Source: Gdk.Types.Gdk_Input_Source) return Gdk.Device.Gdk_Device;
Return the first device that matches the given source. This can be used to simulate keyboard events (using Source_Keyboard) or mouse events (Source_Mouse) for instance. The returned value (if not null) must be Ref-ed before being assigned to an event for instance.