Styles for Morphic

Hello guys,

thinking, how to easily define styles, based on simple selection rules,
i sketched the class, MorphStyle.

The principle how it works is simple:

- you creating a style, add adding actions to it
- you then applying style to morph or group of morphs.

Example:

| style |
style := MorphStyle new
        submorphs
        model: #Browser;
        color: Color red.
style applyTo: World.

Let me describe in detail, what it does, when you applying it:

style applyTo: World.

Style initializing its current selection to be a collection with
single element - { World }.
Next thing, which it does is applying any actions , which we specified
during building the style,
namely:

'submorphs' - replacing the current selection by gathering all
submorphs of it, i.e.

selection before:
 #( World )
selection after:
#( World's submorphs )

'model: #Browser'  - filter the current selection and leave only those
entries, which respond to #model and model class name is #Browser

selection before:
#( world's submorphs )
selection after:
{ Browser SystemWindow#1. Browser SystemWindow#2. Browser
SystemWindow#3.Browser SystemWindow#4. }


'color: Color red'.  - since there's no such method in MorphStyle, it
is trapped by DNU handler and
  converted to a #sendMessage: action.
A #sendMessage: action sends a specified message to current selection, i.e.:

{ Browser SystemWindow#1. .... Browser SystemWindow#N. }
do: [:morph | message sendTo: morph ].

So, as result, if you doIt :
| style |
style := MorphStyle new
        submorphs
        model: #Browser;
        color: Color red.
style applyTo: World.

all browser windows color will be changed to red color.

Some words about potential uses of this stuff.

- theming,  (through defining own style sheets). In contrast to
existing implementation, we're free to define anything, which morph
understands ,
 not just colors, border or fillstyle, but also, layout, fonts,
position etc etc.

- defining styles in various ways:
following snippet sets the 'browse' button color to red for all
browser windows and illustrating how one style could reuse another
one.

| browseButton buttonStyle browsers |

buttonStyle := MorphStyle new color: Color blue.
browseButton := MorphStyle new allSubmorphs; has: #label equalTo: 'browse'.
browsers := MorphStyle new model: #Browser.

browseButton style: buttonStyle. "browseButton reusing buttonStyle"
browsers style: browseButton.  "browser style reusing browseButton style"

browsers applyTo: World submorphs.


It can be easily integrated with Morphic when using some global theme,
all we need is:
- add  Morph>>applyThemeStyles
  ^ World currentTheme applyStylesTo: self

- send #applyStyles to morph, when its added to World.

Also, we could integrate it with toolbuilder which will allow us to define
morph layouts, fonts, colors & initial properties more flexibly than
currently are . Non-morphic builders could just ignore the #setStyles:
message.

Comments, suggestions , as always welcome.

--
Best regards,
Igor Stasenko AKA sig.