Re: Look and Feel

[stefan]

Citát Gregory John Casamento <greg_casamento@yahoo.com>:

<snip>

> Themes in GNUstep are a very different beast than in GNOME or KDE. 
> Typically,
> themes override certain portions of the drawing code in GNUstep to achieve a
> new look.  GNUstep is a complex piece of work and the creation of a new look
> for it is, by no means, a simple task. 
> 

I thought that theme support is included in GUI by a class and creating a theme
is just replacing only that class, is not that true? AFAIR, there was such
class created for this purpose, or not?

If that is not true, then I think that GUI/AppKit should be changed to support
themes natively by delegating drawing of UI elements to some class. Having a
theme bundle to replace drawing methods by poseAs: can be considered a hack. We
are in OO world, then it should be not too difficult to have a class with
methods more methods. Currently there is GSDrawFunctions with methods:

+ (NSRect) drawButton: (NSRect)border : (NSRect)clip;
+ (NSRect) drawDarkButton: (NSRect)border : (NSRect)clip;
+ (NSRect) drawDarkBezel: (NSRect)border : (NSRect)clip;
+ (NSRect) drawLightBezel: (NSRect)border : (NSRect)clip;
+ (NSRect) drawGrayBezel: (NSRect)border : (NSRect)clip;
+ (NSRect) drawWhiteBezel: (NSRect)border : (NSRect)clip;
+ (NSRect) drawGroove: (NSRect)border : (NSRect)clip;
+ (NSRect) drawFramePhoto: (NSRect)border : (NSRect)clip;

+ (NSRect) drawGradientBorder: (NSGradientType)gradientType 
           inRect: (NSRect)border 
           withClip: (NSRect)clip;

If it was extended by more complex methods such as:

+ drawScrollerKnobInRect:clip:
+ drawScrollerArrowInRect:clip:
+ drawPopUpInRect:clip:
+ drawTableHeaderCellWithTitle:rect:clip:
+ drawTabsWithLabels:selectedTabIndex:inRect:clip:
... put all GNUStep UI elements/parts here.

Even more complex methods should be here, if possible:
+ drawColumn:ofBrowser:inRect:clip:

Then GUI should not use drawing by using bezier paths nor DPS operators, it
should use ONLY functions from the "theme class". With this, complete
themability can be achieved without it being a hack, as it is now. This desing
is much cleaner and straightforward. Theme creator does not have to dig into
the AppKit classes to find out "what should be overriden to make the theme
work", moreover the theme  developer will not end by uncomplete theme, as he
knows everything that he should implement.

Stefan Urbanek