Files
sml-projects/fcore/app-update.sml

152 lines
4.5 KiB
Standard ML

structure AppUpdate =
struct
open AppType
open MailboxType
open DrawMsg
open InputMsg
fun resizeText (app: app_type, newWidth, newHeight) =
let
val {buffer, windowWidth, windowHeight, startLine, cursorIdx, ...} = app
val newBuffer = LineGap.goToLine (startLine, buffer)
val drawMsg = TextBuilder.build
(startLine, cursorIdx, newBuffer, newWidth, newHeight)
val newApp = AppWith.bufferAndSize (app, newBuffer, newWidth, newHeight)
in
(newApp, drawMsg)
end
fun moveRight (app: app_type) =
let
val {buffer, windowWidth, windowHeight, startLine, cursorIdx, ...} = app
(* move LineGap to cursorIdx, which is necessary for finding newCursorIdx *)
val buffer = LineGap.goToIdx (cursorIdx, buffer)
val cursorIdx = Cursor.viL (buffer, cursorIdx)
(* move LineGap to first line displayed on screen, and build new text *)
val buffer = LineGap.goToLine (startLine, buffer)
val drawMsg = TextBuilder.build
(startLine, cursorIdx, buffer, windowWidth, windowHeight)
val newApp = AppWith.bufferAndCursorIdx (app, buffer, cursorIdx)
in
(newApp, drawMsg)
end
fun moveLeft (app: app_type) =
let
val {buffer, windowWidth, windowHeight, startLine, cursorIdx, ...} = app
val buffer = LineGap.goToIdx (cursorIdx, buffer)
val cursorIdx = Cursor.viH (buffer, cursorIdx)
val buffer = LineGap.goToLine (startLine, buffer)
val drawMsg = TextBuilder.build
(startLine, cursorIdx, buffer, windowWidth, windowHeight)
val newApp = AppWith.bufferAndCursorIdx (app, buffer, cursorIdx)
in
(newApp, drawMsg)
end
fun moveDown (app: app_type) =
let
val {buffer, windowWidth, windowHeight, startLine, cursorIdx, ...} = app
val buffer = LineGap.goToIdx (cursorIdx, buffer)
val cursorIdx = Cursor.viJ (buffer, cursorIdx)
val buffer = LineGap.goToLine (startLine, buffer)
val drawMsg = TextBuilder.build
(startLine, cursorIdx, buffer, windowWidth, windowHeight)
val newApp = AppWith.bufferAndCursorIdx (app, buffer, cursorIdx)
in
(newApp, drawMsg)
end
fun moveUp (app: app_type) =
let
val {buffer, windowWidth, windowHeight, startLine, cursorIdx, ...} = app
val buffer = LineGap.goToIdx (cursorIdx, buffer)
val cursorIdx = Cursor.viK (buffer, cursorIdx)
val buffer = LineGap.goToLine (startLine, buffer)
val drawMsg = TextBuilder.build
(startLine, cursorIdx, buffer, windowWidth, windowHeight)
val newApp = AppWith.bufferAndCursorIdx (app, buffer, cursorIdx)
in
(newApp, drawMsg)
end
fun moveToLineStart (app: app_type) =
let
val {buffer, windowWidth, windowHeight, startLine, cursorIdx, ...} = app
val buffer = LineGap.goToIdx (cursorIdx, buffer)
val cursorIdx = Cursor.vi0 (buffer, cursorIdx)
val buffer = LineGap.goToLine (startLine, buffer)
val drawMsg = TextBuilder.build
(startLine, cursorIdx, buffer, windowWidth, windowHeight)
val newApp = AppWith.bufferAndCursorIdx (app, buffer, cursorIdx)
in
(newApp, drawMsg)
end
fun moveToLineEnd (app: app_type) =
let
val {buffer, windowWidth, windowHeight, startLine, cursorIdx, ...} = app
val buffer = LineGap.goToIdx (cursorIdx, buffer)
val cursorIdx = Cursor.viDlr (buffer, cursorIdx)
val buffer = LineGap.goToLine (startLine, buffer)
val drawMsg = TextBuilder.build
(startLine, cursorIdx, buffer, windowWidth, windowHeight)
val newApp = AppWith.bufferAndCursorIdx (app, buffer, cursorIdx)
in
(newApp, drawMsg)
end
fun nextWord (app: app_type) =
let
val {buffer, windowWidth, windowHeight, startLine, cursorIdx, ...} = app
val buffer = LineGap.goToIdx (cursorIdx, buffer)
val cursorIdx = Cursor.nextWord (buffer, cursorIdx)
val buffer = LineGap.goToLine (startLine, buffer)
val drawMsg = TextBuilder.build
(startLine, cursorIdx, buffer, windowWidth, windowHeight)
val newApp = AppWith.bufferAndCursorIdx (app, buffer, cursorIdx)
in
(newApp, drawMsg)
end
fun handleChr (app: app_type, chr) =
case chr of
#"h" => moveLeft app
| #"j" => moveDown app
| #"k" => moveUp app
| #"l" => moveRight app
| #"0" => moveToLineStart app
| #"$" => moveToLineEnd app
| #"w" => nextWord app
| _ => (app, [])
fun update (app, msg) =
case msg of
RESIZE_EVENT (width, height) => resizeText (app, width, height)
| CHAR_EVENT chr => handleChr (app, chr)
end