當玩過一陣子Scratch後,有寫過其他程式語言經驗的人,會覺得Scratch這個小玩具有點綁手綁腳,看到官網論壇發表的一堆改裝版(Scratch Mod),一定有衝動想擴充程式積木或其他功能,但是看到陌生的Smalltalk語法後卻又不知從何著手,Jimmy's papa在這裡教大家改裝Scratch也順便幫自己備忘
這是Jimmy's papa打算新增的程式積木,功能是讓程式等待十秒
目標是加到Control分類底下
首先打開SystemBrowser,依下列順序點選各項
>NScratch-Objects>ScriptableScratchMorph>block specs>blockSpecks
可以看到ScriptableScratchMorph類別在blockSpecs這裡定義所屬的每個程式積木的詳細規格,blockSpecs將會回傳一個多維陣列,內含多個分類命名字串(category name)及各分類所屬的程式積木規格說明陣列(Block specificaton Arrays)
程式積木規格說明格式如下
<block spec string> <block type> <selector> [optional initial argument values]
以下是各細項說明
block spec string : 程式積木規格描述字串
block type : 程式積木型態,如K代表鍵盤事件帽, c代表C型包夾命令等等...
selector : 程式積木所對應的選擇子/函數
optional initial argument values:參數預設值
我們可以到下列的程式碼找到('wait %n secs' t wait:elapsed:from: 1)這一行,複製並且插入下一行
將它改成('wait 10 secs' t wait:elapsed:from: 10)
將分類切換一下,可發現屬於Control分類的黃色程式積木多了一個
底下貼出blockSpecs程式碼供大家參考,並附上程式積木型態(block type)的中文說明,試著改改看,可以看到積木外觀型態的改變
blockSpecs
"Answer a collection of block specifications for the blocks that are common to all objects. are interspersed with category names (Strings). A block is an Array of the form: (<block spec string> <block type> <selector> [optional initial argument values]).
Explanation of flags:
- no flags 無
b boolean reporter 布林值回報
c c-shaped block containing a sequence of commands (always special form) C形包夾命令
r reporter 回報
s special form command with its own evaluation rule 特殊格式命令
t timed command, like wait or glide 定時命令
E message event hat 訊息事件帽
K key event hat 鍵盤事件帽
M mouse-click event hat 滑鼠點擊事件帽
S start event hat 起始事件帽
W when <condition> hat (obsolete)"
| blocks |
blocks := #(
'control'
('when %m clicked' S -)
('when %k key pressed' K -)
('when %m clicked' M -)
-
('wait %n secs' t wait:elapsed:from: 1)
-
('forever' c doForever)
('repeat %n' c doRepeat 10)
-
('broadcast %e' - broadcast:)
('broadcast %e and wait' s doBroadcastAndWait)
('when I receive %e' E -)
-
('forever if %b' c doForeverIf)
('if %b' c doIf)
('if %b' c doIfElse)
('wait until %b' s doWaitUntil)
('repeat until %b' c doUntil)
-
('stop script' s doReturn)
('stop all' - stopAll)
'operators'
('%n + %n' r + - -)
('%n - %n' r - - -)
('%n * %n' r * - -)
('%n / %n' r / - -)
-
('pick random %n to %n' r randomFrom:to: 1 10)
-
('%s < %s' b < '' '')
('%s = %s' b = '' '')
('%s > %s' b > '' '')
-
('%b and %b' b &)
('%b or %b' b |)
('not %b' b not)
-
('join %s %s' r concatenate:with: 'hello ' 'world')
('letter %n of %s' r letter:of: 1 'world')
('length of %s' r stringLength: 'world')
-
('%n mod %n' r \\ - -)
('round %n' r rounded -)
-
('%f of %n' r computeFunction:of: 'sqrt' 10)
'sound'
('play sound %S' - playSound:)
('play sound %S until done' s doPlaySoundAndWait)
('stop all sounds' - stopAllSounds)
-
('play drum %D for %n beats' t drum:duration:elapsed:from: 48 0.2)
('rest for %n beats' t rest:elapsed:from: 0.2)
-
('play note %N for %n beats' t noteOn:duration:elapsed:from: 60 0.5)
('set instrument to %I' - midiInstrument: 1)
-
('change volume by %n' - changeVolumeBy: -10)
('set volume to %n%' - setVolumeTo: 100)
('volume' r volume)
-
('change tempo by %n' - changeTempoBy: 20)
('set tempo to %n bpm' - setTempoTo: 60)
('tempo' r tempo)
'motor'
('motor on for %n secs' t motorOnFor:elapsed:from: 1)
('motor on' - allMotorsOn)
('motor off' - allMotorsOff)
('motor power %n' - startMotorPower: 100)
('motor direction %W' - setMotorDirection: 'this way')
'variables'
('show variable %v' - showVariable:)
('hide variable %v' - hideVariable:)
'list'
('add %s to %L' - append:toList: 'thing')
-
('delete %y of %L' - deleteLine:ofList: 1)
('insert %s at %i of %L' - insert:at:ofList: 'thing' 1)
('replace item %i of %L with %s' - setLine:ofList:to: 1 'list' 'thing')
-
('item %i of %L' r getLine:ofList: 1)
('length of %L' r lineCountOfList:)
('%L contains %s' b list:contains: 'list' 'thing')
).
^ blocks, self obsoleteBlockSpecs
