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diff --git a/specs/ch11.xml b/specs/ch11.xml new file mode 100644 index 0000000..39361a4 --- /dev/null +++ b/specs/ch11.xml @@ -0,0 +1,413 @@ + +<chapter id='Keyboard_Geometry'> +<title>Keyboard Geometry</title> + +<para> +The XKB description of a keyboard includes an optional keyboard geometry which +describes the physical appearance of the keyboard. Keyboard geometry describes +the shape, location and color of all keyboard keys or other visible keyboard +components such as indicators. The information contained in a keyboard geometry +is sufficient to allow a client program to draw an accurate two-dimensional +image of the keyboard. +</para> + + +<para> +The components of the keyboard geometry include the following: +</para> + +<itemizedlist> +<listitem> + <para>A <emphasis> +symbolic name</emphasis> + to help users identify the keyboard. + </para> +</listitem> +<listitem> + <para>The <emphasis> +width</emphasis> + and <emphasis> +height</emphasis> + of the keyboard, in <mediaobject> + <imageobject> <imagedata format="SVG" fileref="XKBproto-8.svg"/> + </imageobject> + </mediaobject> +. For non-rectangular keyboards, the width and height describe the smallest +bounding-box that encloses the outline of the keyboard. + </para> +</listitem> +<listitem> + <para>A list of up to <emphasis> +MaxColors</emphasis> + (<emphasis> +32</emphasis> +) <emphasis> +color names</emphasis> +. A color name is a string whose interpretation is not specified by XKB. Other +geometry components refer to colors using their indices in this list. + </para> +</listitem> +<listitem> + <para>The<emphasis> + base color</emphasis> + of the keyboard is the predominant color on the keyboard and is used as the +default color for any components whose color is not explicitly specified. + </para> +</listitem> +<listitem> + <para>The <emphasis> +label color</emphasis> + is the color used to draw the labels on most of the keyboard keys. + </para> +</listitem> +<listitem> + <para>The <emphasis> +label font</emphasis> + is a string which describes the font used to draw labels on most keys; XKB +does not specify a format or name space for font names. + </para> +</listitem> +<listitem> + <para>A list of <emphasis> +geometry properties</emphasis> +. A geometry property associates an arbitrary string with an equally arbitrary +name. Geometry properties can be used to provide hints to programs that display +images of keyboards, but they are not interpreted by XKB. No other geometry +structures refer to geometry properties. + </para> +</listitem> +<listitem> + <para>A list of <emphasis> +key aliases</emphasis> +, as described in <link linkend='Symbolic_Names'>Symbolic +Names</link>. + </para> +</listitem> +<listitem> + <para>A list of <emphasis> +shapes</emphasis> +; other keyboard components refer to shapes by their index in this list. A +shape consists of a name and one or more closed-polygons called <emphasis> +outlines</emphasis> +. Shapes and outlines are described in detail in <link linkend='Shapes_and_Outlines'>Shapes and Outlines</link>. + </para> +</listitem> +</itemizedlist> + +<para> +Unless otherwise specified, geometry measurements are in <mediaobject> + <imageobject> <imagedata format="SVG" fileref="XKBproto-9.svg"/> + </imageobject> + </mediaobject> + + units. The origin (0,0) is in the top left corner of the keyboard image. Some +geometry components can be drawn rotated; all such objects rotate about their +origin in <mediaobject> + <imageobject> <imagedata format="SVG" fileref="XKBproto-10.svg"/> + </imageobject> + </mediaobject> + + increments. +</para> + + +<para> +All geometry components include a <emphasis> +priority</emphasis> +, which indicates the order in which overlapping objects should be drawn. +Objects are drawn in order from highest priority (<emphasis> +0</emphasis> +) to lowest (<emphasis> +255</emphasis> +). +</para> + + +<para> +The description of the actual appearance of the keyboard is subdivided into +named <emphasis> +sections</emphasis> + of related keys and <emphasis> +doodads</emphasis> +. A a <emphasis> +doodad</emphasis> + describes some visible aspect of the keyboard that is not a key. A section is +a collection of keys and doodads that are physically close together and +logically related. +</para> + +<sect1 id='Shapes_and_Outlines'> +<title>Shapes and Outlines</title> + +<para> +An outline is a list of one or more points which describes a single +closed-polygon, as follows: +</para> + +<itemizedlist> +<listitem> + <para>A list with a single point describes a rectangle with one corner at the +origin of the shape (<emphasis> +0</emphasis> +,<emphasis> +0</emphasis> +) and the opposite corner at the specified point. + </para> +</listitem> +<listitem> + <para>A list of two points describes a rectangle with one corner at the +position specified by the first point and the opposite corner at the position +specified by the second point. + </para> +</listitem> +<listitem> + <para>A list of three or more points describes an arbitrary polygon. If +necessary, the polygon is automatically closed by connecting the last point in +the list with the first. + </para> +</listitem> +<listitem> + <para>A non-zero value for the <emphasis> +cornerRadius</emphasis> + field specifies that the corners of the polygon should be drawn as circles +with the specified radius. + </para> +</listitem> +</itemizedlist> + +<para> +All points in an outline are specified relative to the origin of the enclosing +shape. Points in an outline may have negative values for the X and Y coordinate. +</para> + + +<para> +One outline (usually the first) is the primary outline; a keyboard display +application can generate a simpler but still accurate keyboard image by +displaying only the primary outlines for each shape. Non-rectangular keys must +include a rectangular <emphasis> +approximation</emphasis> + as one of the outlines associated with the shape; the approximation is not +normally displayed but can be used by very simple keyboard display applications +to generate a recognizable but degraded image of the keyboard. +</para> + + +</sect1> +<sect1 id='Sections'> +<title>Sections</title> + +<para> +Each section has its own coordinate system — if a section is rotated, the +coordinates of any components within the section are interpreted relative to +the edges that were on the top and left before rotation. The components that +make up a section include: +</para> + +<itemizedlist> +<listitem> + <para>A list of <emphasis> +rows</emphasis> +. A row is a list of horizontally or vertically adjacent keys. Horizontal rows +parallel the (pre-rotation) top of the section and vertical rows parallel the +(pre-rotation) left of the section. All keys in a horizontal row share a common +top coordinate; all keys in a vertical row share a left coordinate. + </para> +<para> +A key description consists of a key <emphasis> +name</emphasis> +, a <emphasis> +shape</emphasis> +, a key <emphasis> +color</emphasis> +, and a <emphasis> +gap</emphasis> +. The key <emphasis> +name</emphasis> + should correspond to one of the keys named in the keyboard names description, +the <emphasis> +shape</emphasis> + specifies the appearance of the key, and the key <emphasis> +color</emphasis> + specifies the color of the key (not the label on the key). Keys are normally +drawn immediately adjacent to one another from left-to-right (or top-to-bottom) +within a row. The <emphasis> +gap</emphasis> + field specifies the distance between a key and its predecessor. + </para> +</listitem> +<listitem> + <para>An optional list of doodads; any type of doodad can be enclosed within +a section. Position and angle of rotation are relative to the origin and angle +of rotation of the sections that contain them. Priority is relative to the +other components of the section, not to the keyboard as a whole. + </para> +</listitem> +<listitem> + <para>An optional list of <emphasis> +overlay keys</emphasis> +. Each overlay key definition indicates a key that can yield multiple scan +codes and consists of a field named <emphasis> +under</emphasis> +, which specifies the primary name of the key and a field named <emphasis> +over</emphasis> +, which specifies the name for the key when the overlay keycode is selected. +The key specified in <emphasis> +under</emphasis> + must be a member of the section that contains the overlay key definition, +while the key specified in over must not. + </para> +</listitem> +</itemizedlist> + +</sect1> +<sect1 id='Doodads'> +<title>Doodads</title> + +<para> +Doodads can be global to the keyboard or part of a section. Doodads have +symbolic names of arbitrary length. The only doodad name whose interpretation +is specified by XKB is "Edges", which describes the outline of the entire +keyboard, if present. +</para> + + +<para> +All doodads report their origin in fields named <emphasis> +left</emphasis> + and <emphasis> +top</emphasis> +. XKB supports five kinds of doodads: +</para> + +<itemizedlist> +<listitem> + <para>An <emphasis> +indicator doodad</emphasis> + describes one of the physical keyboard indicators. Indicator doodads specify +the shape of the indicator, the indicator color when it is lit (<emphasis> +on_color</emphasis> +) and the indicator color when it is dark (<emphasis> +off_color</emphasis> +). + </para> +</listitem> +<listitem> + <para>An <emphasis> +outline doodad</emphasis> + describes some aspect of the keyboard to be drawn as one or more hollow, +closed polygons. Outline doodads specify the shape, color, and angle of +rotation about the doodad origin at which they should be drawn. + </para> +</listitem> +<listitem> + <para>A <emphasis> +solid doodad</emphasis> + describes some aspect of the keyboard to be drawn as one or more filled +polygons. Solid doodads specify the shape, color and angle of rotation about +the doodad origin at which they should be drawn. + </para> +</listitem> +<listitem> + <para>A <emphasis> +text doodad</emphasis> + describes a text label somewhere on the keyboard. Text doodads specify the +label string, the font and color to use when drawing the label, and the angle +of rotation of the doodad about its origin. + </para> +</listitem> +<listitem> + <para>A <emphasis> +logo doodad</emphasis> + is a catch-all, which describes some other visible element of the keyboard. A +logo doodad is essentially an outline doodad with an additional symbolic name +that describes the element to be drawn. + </para> + <para> +If a keyboard display program recognizes the symbolic name, it can draw +something appropriate within the bounding region of the shape specified in the +doodad. If the symbolic name does not describe a recognizable image, it should +draw an outline using the specified shape, outline, and angle of rotation. + </para> + <para> +The XKB extension does not specify the interpretation of logo names. + </para> +</listitem> +</itemizedlist> + +</sect1> +<sect1 id='Keyboard_Geometry_Example'> +<title>Keyboard Geometry Example</title> + +<para> +Consider the following example keyboard: +</para> + +<mediaobject> + <imageobject> + <imagedata format="SVG" fileref="XKBproto-11.svg"/> + </imageobject> +</mediaobject> + + +<para> +This keyboard has six sections: The left and right function sections (at the +very top) each have one horizontal row with eight keys. The left and right +alphanumeric sections (the large sections in the middle) each have six vertical +rows, with four or five keys in each row. The left and right editing sections +each have three vertical rows with one to three keys per row; the left editing +section is rotated 20° clockwise about its origin while the right editing +section is rotated 20° counterclockwise. +</para> + + +<para> +This keyboard has four global doodads: Three small, round indicators and a +rectangular logo. The program which generated this image did not recognize the +logo, so it displays an outline with an appropriate shape in its place. +</para> + + +<para> +This keyboard has seven shapes: All of the keys in the two function sections +use the "FKEY" shape. Most of the keys in the alphanumeric sections, as well as +four of the keys in each of the editing sections use the "NORM" shape. The keys +in the first column of the left alphanumeric section and the last column of the +right alphanumeric section all use the "WIDE" shape. Two keys in each of the +editing sections use the "TALL" shape. The "LED" shape describes the three +small, round indicators between the function and alphabetic sections. The +"LOGO" shape describes the keyboard logo, and the "EDGE" shape describes the +outline of the keyboard as a whole. +</para> + + +<para> +The keyboard itself is white, as are all of the keys except for the eight keys +that make up the home row, which use the "grey20" color. It isn’t really +visible in this picture, but the three indicators have an "on" color of "green" +and are "green30" when they are turned off. The keys in the alphanumeric and +editing sections all have a (vertical) gap of 0.5mm; the keys in the two +function sections have a (horizontal) gap of 3mm. +</para> + + +<para> +Many of the keys in the right alphanumeric section, and the rightmost key in +the right editing section are drawn with two names in this image. Those are +overlay keys; the bottom key name is the normal name while the overlay name is +printed at the top. For example, the right editing section has a single overlay +key entry, which specifies an <emphasis> +under</emphasis> + name of <emphasis> +<SPCE></emphasis> + and an <emphasis> +over</emphasis> + name of <emphasis> +<KP0></emphasis> +, which indicates that the key in question is usually the shift key, but can +behave like the <emphasis> +0</emphasis> + key on the numeric keypad when an overlay is active. +</para> +</sect1> +</chapter> |