59 lines
1.8 KiB
Standard ML
59 lines
1.8 KiB
Standard ML
structure AppUpdate =
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struct
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open AppType
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open MailboxType
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open DrawMsg
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open InputMsg
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fun resizeText (app: app_type, newWidth, newHeight) =
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let
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val {buffer, windowWidth, windowHeight, startLine, cursorIdx} = app
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val newBuffer = LineGap.goToLine (startLine, buffer)
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val drawMsg = TextBuilder.build
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(startLine, cursorIdx, newBuffer, newWidth, newHeight)
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val newApp = AppWith.bufferAndSize (app, newBuffer, newWidth, newHeight)
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in
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(newApp, drawMsg)
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end
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fun moveRight (app: app_type) =
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let
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(* todo: proper implementation of moveRight
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* currently, we also retrieve the newCursorIdx improperly.
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* To do it properly, we have to look inside LineGap
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* instead of just incrementing cursorIdx by 1.
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* So:
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* - Find newCursorIdx from LineGap
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* *)
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val {buffer, windowWidth, windowHeight, startLine, cursorIdx} = app
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(* move LineGap to cursorIdx, which is necessary for finding newCursorIdx *)
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val newBuffer = LineGap.goToIdx (cursorIdx, buffer)
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(* todo: call to retrieve newCursorIdx should be below *)
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val newCursorIdx = cursorIdx + 1
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(* move LineGap to first line displayed on screen, and build new text *)
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val newBuffer = LineGap.goToLine (startLine, newBuffer)
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val drawMsg = TextBuilder.build
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(startLine, cursorIdx, newBuffer, windowWidth, windowHeight)
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val newApp = AppWith.bufferAndCursorIdx (app, newBuffer, newCursorIdx)
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in
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(newApp, drawMsg)
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end
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fun handleChr (app: app_type, chr) =
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case chr of
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#"l" => moveRight app
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| _ => (app, [])
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fun update (app, msg) =
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case msg of
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RESIZE_EVENT (width, height) => resizeText (app, width, height)
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| CHAR_EVENT chr => handleChr (app, chr)
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end
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