evan
7c0928d84e
The firmware now fires on_touch_move with a 2px noise threshold; gesture intent is the toolkit's 8px slop, since a painting app's stroke starts at the first real pixel. Past the slop, Screen:move hands the drag to the nearest scroll ancestor and cancels the widget under the finger. ui.scroll leans on the app viewport for clipping, so it must reach both panel edges. Paint and Scroll demo both halves of the gesture split.
49 lines
1.2 KiB
Lua
49 lines
1.2 KiB
Lua
local ui = require("ui")
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-- No components: a canvas has one gesture and every pixel is content, so the app takes
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-- the touch callbacks raw. It wants the firmware's noise threshold and no gesture slop --
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-- a three pixel stroke is a stroke, not a mis-tap.
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local theme = ui.theme
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local CLEAR = {x = 0, y = 0, w = 64, h = 28}
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local BRUSH = 2
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local lastX, lastY
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local function inClear(x, y)
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return x < CLEAR.w and y < CLEAR.h
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end
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local function clear()
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gui.clear(theme.bg)
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gui.roundRect(CLEAR.x, CLEAR.y, CLEAR.w, CLEAR.h, theme.radius, theme.bg,
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theme.face[1], theme.face[2], theme.fg)
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gui.drawText("clear", 14, 10, theme.fg)
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end
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function init()
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clear()
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log.info("paint ready")
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end
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function on_touch_down(x, y)
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if inClear(x, y) then
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lastX = nil
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return clear()
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end
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lastX, lastY = x, y
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gui.fillCircle(x, y, BRUSH, theme.accent)
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end
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-- Strokes are joined with a line because the poll rate, not the finger, decides the gap:
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-- a fast swipe reports points tens of pixels apart and dots alone would look dotted.
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function on_touch_move(x, y)
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if not lastX then return end
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gui.drawLine(lastX, lastY, x, y, theme.accent)
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gui.fillCircle(x, y, BRUSH, theme.accent)
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lastX, lastY = x, y
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end
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function on_touch_up()
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lastX = nil
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end
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