examples/text_editor: make scrolling smoother (#6819)

pull/6830/head
spaceface777 2020-11-14 08:21:46 +01:00 committed by GitHub
parent 6b47c61fe4
commit ec3b96924f
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1 changed files with 33 additions and 26 deletions

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@ -4,7 +4,7 @@
// A lot of funtionality is missing compared to your favourite editor :)
import strings
import os
import term.ui
import term.ui as tui
enum Movement {
up
@ -23,12 +23,13 @@ pub:
struct App {
mut:
tui &ui.Context = 0
tui &tui.Context = 0
ed &Buffer = 0
file string
status string
t int
footer_height int = 2
viewport int
}
fn (mut a App) set_status(msg string, duration_ms int) {
@ -49,22 +50,30 @@ fn (mut a App) save() {
fn (mut a App) footer() {
w, h := a.tui.window_width, a.tui.window_height
mut b := a.ed
flat := b.flat()
snip := if flat.len > 19 { flat[..20] } else { flat }
// flat := b.flat()
// snip := if flat.len > 19 { flat[..20] } else { flat }
mut finfo := ''
if a.file.len > 0 {
finfo = ' (' + os.file_name(a.file) + ')'
}
mut status := a.status
a.tui.draw_text(0, h - 1, ''.repeat(w))
footer := '$finfo Line ${b.cursor.pos_y + 1:4}/${b.lines.len:-4}, Column ${b.cursor.pos_x + 1:3}/${b.cur_line().len:-3} index: ${b.cursor_index():5} (ESC = quit, Ctrl+s = save)'
if footer.len < w {
a.tui.draw_text((w - footer.len) / 2, h, footer)
} else if footer.len == w {
a.tui.draw_text(0, h, footer)
} else {
a.tui.draw_text(0, h, footer[..w])
}
if a.t <= 0 {
status = ''
}
line := ''.repeat(w) + '\n'
footer := line + '$finfo Line ${b.cursor.pos_y + 1:4}/${b.lines.len:-4}, Column ${b.cursor.pos_x + 1:3}/${b.cur_line().len:-3} index: ${b.cursor_index():5} (ESC = quit, Ctrl+s = save) Raw: "$snip" $status'
a.tui.draw_text(0, h - 1, footer)
} else {
a.tui.set_bg_color(r: 200, g: 200, b: 200)
a.tui.set_color(r: 0, g: 0, b: 0)
a.tui.draw_text((w + 4 - status.len) / 2, h - 1, ' $status ')
a.tui.reset()
a.t -= 33
if a.t < 0 {
a.t = 0
}
}
@ -340,6 +349,7 @@ fn init(x voidptr) {
}
}
if os.is_file(app.file) {
app.tui.set_window_title(/* 'vico: ' + */app.file)
mut b := app.ed
content := os.read_file(app.file) or {
panic(err)
@ -355,24 +365,22 @@ fn frame(x voidptr) {
mut app := &App(x)
mut ed := app.ed
app.tui.clear()
scroll_limit := app.tui.window_height-app.footer_height-1
mut view := View{}
if ed.cursor.pos_y > scroll_limit { // Scroll
view = ed.view(ed.cursor.pos_y-scroll_limit, ed.cursor.pos_y)
} else {
view = ed.view(0, scroll_limit)
// scroll down
if ed.cursor.pos_y > app.viewport+scroll_limit { // scroll down
app.viewport = ed.cursor.pos_y-scroll_limit
} else if ed.cursor.pos_y < app.viewport { // scroll up
app.viewport = ed.cursor.pos_y
}
view := ed.view(app.viewport, scroll_limit+app.viewport)
app.tui.draw_text(0, 0, view.raw)
app.footer()
if ed.cursor.pos_y > scroll_limit {
app.tui.set_cursor_position(view.cursor.pos_x + 1, scroll_limit+1)
} else {
app.tui.set_cursor_position(view.cursor.pos_x + 1, view.cursor.pos_y + 1)
}
app.tui.set_cursor_position(view.cursor.pos_x + 1, ed.cursor.pos_y + 1 - app.viewport)
app.tui.flush()
}
fn event(e &ui.Event, x voidptr) {
fn event(e &tui.Event, x voidptr) {
mut app := &App(x)
mut buffer := app.ed
if e.typ == .key_down {
@ -407,11 +415,11 @@ fn event(e &ui.Event, x voidptr) {
buffer.move_cursor(1, .end)
}
48...57, 97...122 { // 0-9a-zA-Z
if e.modifiers == ui.ctrl {
if e.modifiers == tui.ctrl {
if e.code == .s {
app.save()
}
} else if e.modifiers in [ui.shift, 0] {
} else if e.modifiers in [tui.shift, 0] {
buffer.put(e.ascii.str())
}
}
@ -433,12 +441,11 @@ if os.args.len > 1 {
mut app := &App{
file: file
}
app.tui = ui.init({
app.tui = tui.init({
user_data: app
init_fn: init
frame_fn: frame
event_fn: event
capture_events: true
frame_rate: 30
})
app.tui.run()