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Authors
- Adam Fedor (
fedor@gnu.org
)
-
- Richard Frith-Macdonald (
rfm@gnu.org
)
-
Useful/configurable drawing functions
Copyright: (C) 2004-2006 Free Software Foundation, Inc.
The theme management system for the GNUstep GUI is based
around the
GSTheme
class, which provides support for loading of theme
bundles and methods for drawing common user interface
elements.
The theme system works in
conjunction with a variety of other GUI classes
and is intended to eventually allow for very major
changes in GUI appearance and behavior.
Various design imperatives apply to the theme system,
but probably the key ones are:
-
It should allow designers and other non-technical users
to easily develop new and interesting GUI styles likely
to attract new users to GNUstep.
-
Using and switching between themes should be an easy
and pleasant experience... so that people are not put
off when they try using themes.
-
It should eventually permit a GNUstep application to
appear as a native application on ms-windows and
other systems.
To attain these aims implies the recognition of some more
specific objectives and some possible technical
solutions:
-
We must have as simple as possible an API for the
functions handling the way GUI elements work and
the way they draw themselves.
The standard
OpenStep/MacOS-X API provides mechanisms
for controlling the colors used to draw controls (via
NSColor
and
NSColorList
) and controlling the way controls behave
(NSInterfaceStyleForKey() and
[NSResponder -interfaceStyle]
), but we need to extend that with methods to draw controls entirely differently if required.
-
We must have a GUI application for theme
development. It is not sufficient to
provide an API if we want good graphic
designers and user interface specialists to
develop themes for us.
-
It must be possible for an application to
dynamically change the theme in use while
it is running and it should be easy for a user to
select between available themes.
This
implies that themes must be loadable bundles
and that it must always be possible to unload a
theme as well as loading one.
It suggests
that the theme selection mechanism should be in
every application, perhaps as an extension to an
existing panel such as the info panel.
There are various aspects of theming which can be
treated pretty much separately, so there is no
reason why a theme might not be created which
just employs one of these mechanisms.
- System images
-
Possibly the simples theme change... a theme
might supply a new set of system images used
for arrows and other icons that the GUI decorates
controls with.
- System colors
-
A theme might simply define a new system color
list, so that controls are drawn in a new color
range, though they would still function the
same way. Even specifying new colors can make
the GUI look quite different though.
- Image tiling
-
Controls might be given sets of images used
as tiling to draw themselves rather than using the
standard line drawing and color fill
mechanisms.
- Interface style
-
A theme might supply a set of interface style keys
for various controls, defining how those controls
should behave subject to the limitation of the
range of behaviors coded into the GUI library.
- Method override
-
A theme might actually provide code, in the form of
a subclass of
GSTheme
such that drawing methods have completely
custom behavior.
- Declared in:
- GNUstepGUI/GSTheme.h
Availability: Not in OpenStep/MacOS-X
This interface is HIGHLY unstable
and incomplete at present.
This is a class used for 'theming', which is mostly a
matter of encapsulating common drawing behaviors so
that GUI appearance can be easily modified, but also
includes mechanisms for altering some GUI behavior
(such mas orientation and position of menus).
Methods in this class standardize drawing of
buttons, borders and other common GUI elements, so
that all other classes within the GUI will provide a
consistent appearance by using these methods.
The default implementation uses the standard
configurable colors defined in NSColor, such
as controlLightHighlightColor
,
controlShadowColor
and
controlDarkShadowColor
.
Themes
are expected to override the default system color list
with their own versions, and this class cooperates
with
NSColor
and
NSColorList
to establish the correct system color list when a
theme is activated.
The class provides a mechanism for automatic
loading of theme bundles consisting of
resources used to define how drawing is done,
plus an optional binary subclass of this class (to
replace/extend the drawing methods this
class provides).
In future this class should provide mechanisms to
draw controls by tiling of images, and provide
control over GUI behavior by controlling the
values returned by
NSInterfaceStyleForKey()
so that controls use the appropriate behavior.
Method summary
+ (void)
orderFrontSharedThemePanel: (id)sender;
Availability: Not in OpenStep/MacOS-X
Creates and displays a panel allowing selection of
different themes and display of the current theme
inspector.
+ (void)
setTheme: (
GSTheme*)theme;
Availability: Not in OpenStep/MacOS-X
Set the currently active theme to be the
instance specified.
You do not normally
need to call this method as it is called automatically
when the user default which specifies the current
theme (GSTheme) is updated.
+ (
GSTheme*)
theme;
Availability: Not in OpenStep/MacOS-X
Returns the currently active theme instance. This
is the value most recently set using
+setTheme:
or (if none has been set) is a default instance of the
base class.
- (void)
activate;
Availability: Not in OpenStep/MacOS-X
This method is called automatically when the
receiver is made into the currently active theme
by the
+setTheme:
method. Subclasses may override it to perform
startup operations, but should call the super
class implementation after doing their own thing.
The base implementation handles setup and caching of
the system color list, standard image information,
tiling information, and user defaults.
It
then sends a GSThemeDidActivateNotification to allow
other parts of the GUI library to update themselves
from the new theme.
If the theme sets an
alternative system color list, the
notification userInfo dictionary will
contain that list keyed on Colors.
Finally, this method marks all windows in the
application as needing update... so they will
draw themselves with the new theme information.
- (
NSArray*)
authors;
Availability: Not in OpenStep/MacOS-X
Returns the names of the theme's authors.
- (
NSBundle*)
bundle;
Availability: Not in OpenStep/MacOS-X
Return the bundle containing the resources used by
the current theme.
- (void)
deactivate;
Availability: Not in OpenStep/MacOS-X
This method is called automatically when the
receiver is stopped from being the currently
active theme by the use of the
+setTheme:
method to make another theme active. Subclasses
may override it to perform shutdown operations, but
should call the super class implementation after
their own.
The base implementation handles some cleanup and then
sends a GSThemeDidDeactivateNotification to allow
other parts of the GUI library to update
themselves.
- (
NSImage*)
icon;
Availability: Not in OpenStep/MacOS-X
Returns the theme's icon.
- (
NSDictionary*)
infoDictionary;
Availability: Not in OpenStep/MacOS-X
Returns the info dictionary for this theme. In
the base class implementation this is simply the info
dictionary of the theme bundle, but subclasses
may override this method to return extra or different
information.
Keys found in this dictionary include:
- GSThemeDomain
-
A dictionary whose key/value pairs are used to set up
new values in the GSThemeDomain domain of the user
defaults system, and hence define values for
these unless overridden by values set explicitly
by the user.
- GSThemeTiles
-
A dictionary keyed on tile names and containing the
following:
- FileName
-
Name of the file (within the GSThemeTiles
directory in the bundle) in which the
image for this tile is tored.
- HorizontalDivision
-
The offet along the X-axis used to divide the
image into columns of tiles.
- VerticalDivision
-
The offet along the Y-axis used to divide the
image into rows of tiles.
- (id)
initWithBundle: (
NSBundle*)bundle;
Availability: Not in OpenStep/MacOS-X
This is a designated initialiser for the class.
Initialise an instance of a theme with the
specified resource bundle.
You
don't need to call this method directly, but if you
are subclassing you may need to override this to
provide additional initialisation.
- (
NSString*)
name;
Availability: Not in OpenStep/MacOS-X
Return the theme's name.
- (
NSWindow*)
themeInspector;
Availability: Not in OpenStep/MacOS-X
Provides a standard inspector window used to
display information about the receiver. The
default implementation displays the icon, the
name, and the authors of the theme.
The code managing this object (if any) must be
prepared to have the content view of the window
reparented into another window for display on
screen.
- (GSDrawTiles*)
tilesNamed: (
NSString*)aName
cache: (BOOL)useCache;
Availability: Not in OpenStep/MacOS-X
Returns the tile image information for a particular
image name, or
nil
if there is no such
information.
The GUI library uses this
internally to handling tiling of image
information to draw user interface elements.
The tile information returned by this method can be
passed to the
-fillRect:withTiles:background:fillStyle:
method.
The
useCache argument controls whether the information is retrieved from cache or regenerated from information in the theme bundle.
- Declared in:
- GNUstepGUI/GSTheme.h
Availability: Not in OpenStep/MacOS-X
Theme drawing methods
Method summary
- (
NSSize)
buttonBorderForStyle: (int)style
state: (
GSThemeControlState)state;
Availability: Not in OpenStep/MacOS-X
Amount by which the button is inset by the border.
- (void)
drawButton: (
NSRect)frame
in: (
NSButtonCell*)cell
view: (
NSView*)view
style: (int)style
state: (
GSThemeControlState)state;
Availability: Not in OpenStep/MacOS-X
Draws a button frame and background (not
its content) for the specified cell and
view.
- (void)
drawFocusFrame: (
NSRect)frame
view: (
NSView*)view;
Availability: Not in OpenStep/MacOS-X
Draws the indicator (normally a dotted rectangle) to
show that the view currently has keyboard
focus.
- (void)
drawWindowBackground: (
NSRect)frame
view: (
NSView*)view;
Availability: Not in OpenStep/MacOS-X
Draws the background of a window... normally a simple
fill with the the window's background color.
- Declared in:
- GNUstepGUI/GSTheme.h
Availability: Not in OpenStep/MacOS-X
Low level drawiong methods... themes may use these for
drawing, but should not normally override them.
Method summary
- (void)
fillHorizontalRect: (
NSRect)rect
withImage: (
NSImage*)image
fromRect: (
NSRect)source
flipped: (BOOL)flipped;
Availability: Not in OpenStep/MacOS-X
Method to tile the supplied image to fill
the horizontal rectangle.
The rect
argument is the rectangle to be filled.
The
image argument is the data to fill with.
The source argument is the
rectangle within the image which is
used.
The flipped argument
specifies what sort of coordinate system is in
use in the view where we are drawing.
- (void)
fillRect: (
NSRect)rect
withRepeatedImage: (
NSImage*)image
fromRect: (
NSRect)source
center: (BOOL)center;
Availability: Not in OpenStep/MacOS-X
Tile rect with image. The tiling
starts with the origin of the first copy of the
image at the bottom left corner of the
rect unless center is
YES
, in which case the image
is centered in rect and tiled outwards from
that.
- (
NSRect)
fillRect: (
NSRect)rect
withTiles: (GSDrawTiles*)tiles
background: (
NSColor*)color
fillStyle: (
GSThemeFillStyle)style;
Availability: Not in OpenStep/MacOS-X
Method to tile a rectangle given a group of up to
nine tile images.
The GSDrawTiles object
encapsulates the tile images and information
about what parts of each image are used for tiling.
This draws the left, right, top and bottom
borders by tiling the images at left, right, top
and bottom. It then draws the four corner images and
finally deals with the remaining space in the
middle according to the specified style.
The background color specified is
used to fill the center where style is
FillStyleNone.
The return value is
the central rectangle (inside the border images).
- (void)
fillVerticalRect: (
NSRect)rect
withImage: (
NSImage*)image
fromRect: (
NSRect)source
flipped: (BOOL)flipped;
Availability: Not in OpenStep/MacOS-X
Method to tile the supplied image to fill
the vertical rectangle.
The rect
argument is the rectangle to be filled.
The
image argument is the data to fill with.
The source argument is the
rectangle within the image which is
used.
The flipped argument
specifies what sort of coordinate system is in
use in the view where we are drawing.
- Declared in:
- GNUstepGUI/GSTheme.h
Availability: Not in OpenStep/MacOS-X
Helper functions for drawing standard items.
Method summary
- (
NSRect)
drawButton: (
NSRect)border
withClip: (
NSRect)clip;
Availability: Not in OpenStep/MacOS-X
Draw a standard button
- (
NSRect)
drawDarkBezel: (
NSRect)border
withClip: (
NSRect)clip;
Availability: Not in OpenStep/MacOS-X
Draw a dark bezel border
- (
NSRect)
drawDarkButton: (
NSRect)border
withClip: (
NSRect)clip;
Availability: Not in OpenStep/MacOS-X
Draw a "dark" button border (used in
tableviews)
- (
NSRect)
drawFramePhoto: (
NSRect)border
withClip: (
NSRect)clip;
Availability: Not in OpenStep/MacOS-X
Draw a frame photo border. Used in
NSImageView.
- (
NSRect)
drawGradientBorder: (
NSGradientType)gradientType
inRect: (
NSRect)border
withClip: (
NSRect)clip;
Availability: Not in OpenStep/MacOS-X
Draw a gradient border.
- (
NSRect)
drawGrayBezel: (
NSRect)border
withClip: (
NSRect)clip;
Availability: Not in OpenStep/MacOS-X
Draw a grey bezel border
- (
NSRect)
drawGroove: (
NSRect)border
withClip: (
NSRect)clip;
Availability: Not in OpenStep/MacOS-X
Draw a groove border
- (
NSRect)
drawLightBezel: (
NSRect)border
withClip: (
NSRect)clip;
Availability: Not in OpenStep/MacOS-X
Draw a light bezel border
- (
NSRect)
drawWhiteBezel: (
NSRect)border
withClip: (
NSRect)clip;
Availability: Not in OpenStep/MacOS-X
Draw a white bezel border
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