GUICanvasWML

From The Battle for Wesnoth Wiki



Canvas

A canvas is a blank drawing area on which the user can draw several shapes. The drawing is done by adding WML structures to the canvas.

Pre commit

This section contains the pre commit functions. These functions will be executed before the drawn canvas is applied on top of the normal background. There should only be one pre commit section and its order regarding the other shapes doesn't matter. The function has effect on the entire canvas, it's not possible to affect only a small part of the canvas.

The section can have one of the following subsections.

Blur

Blurs the background before applying the canvas. This doesn't make sense if the widget isn't semi-transparent.

Keys:

key type default description
depth unsigned 0 The depth to blur.


Line

Definition of a line. When drawing a line it doesn't get blended on the surface but replaces the pixels instead. A blitting flag might be added later if needed.

Keys:

key type default description
x1 f_unsigned 0 The x coordinate of the startpoint.
y1 f_unsigned 0 The y coordinate of the startpoint.
x2 f_unsigned 0 The x coordinate of the endpoint.
y2 f_unsigned 0 The y coordinate of the endpoint.
color color "" The color of the line.
thickness unsigned 0 The thickness of the line if 0 nothing is drawn.
debug string "" Debug message to show upon creation this message is not stored.


Variables:.

Variable type description
width unsigned The width of the canvas.
height unsigned The height of the canvas.
text tstring The text to render on the widget.
text_maximum_width unsigned The maximum width available for the text on the widget.
text_maximum_height unsigned The maximum height available for the text on the widget.
text_wrap_mode int When the text doesn't fit in the available width there are several ways to fix that. This variable holds the best method. (NOTE this is a 'hidden' variable meant to copy state from a widget to its canvas so there's no reason to use this variable and thus its values are not listed and might change without further notice.)
text_alignment h_align The way the text is aligned inside the canvas.

The size variables are copied to the window and will be determined at runtime. This is needed since the main window can be resized and the dialog needs to resize accordingly. The following variables are available:

Variable type description
screen_width unsigned The usable width of the Wesnoth main window.
screen_height unsigned The usable height of the Wesnoth main window.
gamemapx_offset unsigned The distance between left edge of the screen and the game map.
gamemap_width unsigned The usable width of the Wesnoth gamemap, if no gamemap shown it's the same value as screen_width.
gamemap_height unsigned The usable height of the Wesnoth gamemap, if no gamemap shown it's the same value as screen_height.
mouse_x unsigned The x coordinate of the mouse pointer.
mouse_y unsigned The y coordinate of the mouse pointer.
window_width unsigned The window width. This value has two meanings during the layout phase. This only applies if automatic placement is not enabled. - When set to 0 it should return the wanted maximum width. If no maximum is wanted it should be set to the '"(screen_width)"'. - When not equal to 0 its value is the best width for the window. When the size should remain unchanged it should be set to '"(window_width)"'.
window_height unsigned The window height. This value has two meanings during the layout phase. This only applies if automatic placement is not enabled. - When set to 0 it should return the wanted maximum height. If no maximum is wanted it should be set to the '"(screen_height)"'. - When not equal to 0 its value is the best height for the window. When the size should remain unchanged it should be set to '"(window_height)"'.

Note when drawing the valid coordinates are:
0 -> width - 1
0 -> height -1

Drawing outside this area will result in unpredictable results including crashing. (That should be fixed, when encountered.)

Rectangle

Definition of a rectangle. When drawing a rectangle it doesn't get blended on the surface but replaces the pixels instead. A blitting flag might be added later if needed.

Keys:

key type default description
x f_unsigned 0 The x coordinate of the top left corner.
y f_unsigned 0 The y coordinate of the top left corner.
w f_unsigned 0 The width of the rectangle.
h f_unsigned 0 The height of the rectangle.
border_thickness unsigned 0 The thickness of the border if the thickness is zero it's not drawn.
border_color color "" The color of the border if empty it's not drawn.
fill_color color "" The color of the interior if omitted it's not drawn.
debug string "" Debug message to show upon creation this message is not stored.

Variables: See Line.

Circle

Definition of a circle. When drawing a circle it doesn't get blended on the surface but replaces the pixels instead. A blitting flag might be added later if needed.

Keys:

key type default description
x f_unsigned 0 The x coordinate of the center.
y f_unsigned 0 The y coordinate of the center.
radius f_unsigned 0 The radius of the circle if 0 nothing is drawn.
color color "" The color of the circle.
debug string "" Debug message to show upon creation this message is not stored.

Variables: See Line.

Drawing outside the area will result in unpredictable results including crashing. (That should be fixed, when encountered.)

Image

Definition of an image.

Keys:

key type default description
x f_unsigned 0 The x coordinate of the top left corner.
y f_unsigned 0 The y coordinate of the top left corner.
w f_unsigned 0 The width of the image, if not zero the image will be scaled to the desired width.
h f_unsigned 0 The height of the image, if not zero the image will be scaled to the desired height.
resize_mode resize_mode scale Determines how an image is scaled to fit the wanted size.
vertical_mirror f_bool false Mirror the image over the vertical axis.
name f_string "" The name of the image.
debug string "" Debug message to show upon creation this message is not stored.

Variables:

Variable type description
image_width unsigned The width of the image, either the requested width or the natural width of the image. This value can be used to set the x (or y) value of the image. (This means x and y are evaluated after the width and height.)
image_height unsigned The height of the image, either the requested height or the natural height of the image. This value can be used to set the y (or x) value of the image. (This means x and y are evaluated after the width and height.)
image_original_width unsigned The width of the image as stored on disk, can be used to set x or w (also y and h can be set).
image_original_height unsigned The height of the image as stored on disk, can be used to set y or h (also x and y can be set).

Also the general variables are available, see Line.

Text

Definition of text.

Keys:

key type default description
x f_unsigned 0 The x coordinate of the top left corner.
y f_unsigned 0 The y coordinate of the top left corner.
w f_unsigned 0 The width of the text's bounding rectangle.
h f_unsigned 0 The height of the text's bounding rectangle.
font_family font_family "sans" The font family used for the text.
font_size unsigned mandatory The size of the text font.
font_style font_style "" The style of the text.
text_alignment f_h_align "left" The alignment of the text.
color color "" The color of the text.
text f_tstring "" The text to draw (translatable).
text_markup f_bool false Can the text have mark-up?
text_link_aware f_bool false Is the text link aware?
text_link_color f_string "#ffff00" The color of links in the text
maximum_width f_int -1 The maximum width the text is allowed to be.
maximum_height f_int -1 The maximum height the text is allowed to be.
debug string "" Debug message to show upon creation this message is not stored.

NOTE alignment could only be done with the formulas, but now with the text_alignment flag as well, older widgets might still use the formulas and not all widgets may expose the text alignment yet and when exposed not use it yet.

Variables:

Variable type description
text_width unsigned The width of the rendered text.
text_height unsigned The height of the rendered text.

Also the general variables are available, see Line.

This page was last modified on 16 August 2015, at 01:47.