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koreader/frontend/ui/widget/container/movablecontainer.lua
poire-z 8036ca0d56 MovableContainer: add support for anchoring initial position
When passing as 'anchor' a Geom object (ie. a widget dimen
or a ges.pos), or a function returning such an object,
a MovableContainer will be initially positionned near this
point/widget, instead of being centered on the screen.
Allow that for ButtonDialog and ButtonDialogTitle, so we
can make them behave as context menus (ie. for a titlebar
top left/right icons).
2023-03-23 20:28:38 +01:00

419 lines
16 KiB
Lua

--[[--
A MovableContainer can have its content moved on screen
with Swipe/Hold/Pan.
Can optionally apply alpha transparency to its content.
With Swipe: the widget will be constrained to screen borders.
With Hold and pan, the widget can overflow the borders.
Hold with no move will reset the widget to its original position.
If the widget has not been moved or is already at its original
position, Hold will toggle between full opacity and 0.7 transparency.
This container's content is expected to not change its width and height.
]]
local BD = require("ui/bidi")
local Blitbuffer = require("ffi/blitbuffer")
local Device = require("device")
local Geom = require("ui/geometry")
local GestureRange = require("ui/gesturerange")
local InputContainer = require("ui/widget/container/inputcontainer")
local Math = require("optmath")
local UIManager = require("ui/uimanager")
local Screen = Device.screen
local logger = require("logger")
local MovableContainer = InputContainer:extend{
-- Alpha value for subwidget transparency
-- 0 = fully invisible, 1 = fully opaque (0.6 / 0.7 / 0.8 are some interesting values)
alpha = nil,
-- Move threshold (if move distance less than that, considered as a Hold
-- with no movement, used for reseting move to original position)
move_threshold = Screen:scaleBySize(5),
-- Events to ignore (ie: ignore_events={"hold", "hold_release"})
ignore_events = nil,
-- Initial position can be set related to an existing widget
-- 'anchor' should be a Geom object (a widget's 'dimen', or a point), and
-- can be a function returning that object
anchor = nil,
_anchor_ensured = nil,
-- Current move offset (use getMovedOffset()/setMovedOffset() to access them)
_moved_offset_x = 0,
_moved_offset_y = 0,
-- Internal state between events
_touch_pre_pan_was_inside = false,
_moving = false,
_move_relative_x = nil,
_move_relative_y = nil,
-- Original painting position from outer widget
_orig_x = nil,
_orig_y = nil,
-- We cache a compose canvas for alpha handling
compose_bb = nil,
}
function MovableContainer:init()
if Device:isTouchDevice() then
local range = Geom:new{
x = 0, y = 0,
w = Screen:getWidth(),
h = Screen:getHeight(),
}
-- Unflatten self.ignore_events to table keys for cleaner code below
local ignore = {}
if self.ignore_events then
for _, evname in pairs(self.ignore_events) do
ignore[evname] = true
end
end
-- The following gestures need to be supported, depending on the
-- ways a user can move things:
-- Hold happens if he holds at start
-- Pan happens if he doesn't hold at start, but holds at end
-- Swipe happens if he doesn't hold at any moment
-- Note that Swipe is tied to 0/45/90/135 degree... directions,
-- which is somehow nice and gives a kind of magnetic move that
-- stick the widget to some invisible rulers.
-- (Touch is needed for accurate pan)
self.ges_events = {
MovableTouch = not ignore.touch and { GestureRange:new{ ges = "touch", range = range } } or nil,
MovableSwipe = not ignore.swipe and { GestureRange:new{ ges = "swipe", range = range } } or nil,
MovableHold = not ignore.hold and { GestureRange:new{ ges = "hold", range = range } } or nil,
MovableHoldPan = not ignore.hold_pan and { GestureRange:new{ ges = "hold_pan", range = range } } or nil,
MovableHoldRelease = not ignore.hold_release and { GestureRange:new{ ges = "hold_release", range = range } } or nil,
MovablePan = not ignore.pan and { GestureRange:new{ ges = "pan", range = range } } or nil,
MovablePanRelease = not ignore.pan_release and { GestureRange:new{ ges = "pan_release", range = range } } or nil,
}
end
end
function MovableContainer:getMovedOffset()
return Geom:new{
x = self._moved_offset_x,
y = self._moved_offset_y,
}
end
function MovableContainer:setMovedOffset(offset_point)
if offset_point and offset_point.x and offset_point.y then
self._moved_offset_x = offset_point.x
self._moved_offset_y = offset_point.y
end
end
function MovableContainer:ensureAnchor(x, y)
local anchor_dimen = self.anchor
local prefers_pop_down
if type(self.anchor) == "function" then
anchor_dimen, prefers_pop_down = self.anchor()
end
if not anchor_dimen then
return
end
-- We try to find the best way to draw our content, depending on
-- the size of the content and the space available on the screen.
local content_w, content_h = self.dimen.w, self.dimen.h
local screen_w, screen_h = Screen:getWidth(), Screen:getHeight()
local left, top
if BD.mirroredUILayout() then
left = anchor_dimen.x + anchor_dimen.w - content_w
else
left = anchor_dimen.x
end
if left < 0 then
left = 0
elseif left + content_w > screen_w then
left = screen_w - content_w
end
-- We prefer displaying above the anchor if there is room (so it looks like popping up)
-- except if anchor() returned prefers_pop_down
local h_remaining_if_above = anchor_dimen.y - content_h
local h_remaining_if_below = screen_h - (anchor_dimen.y + anchor_dimen.h + content_h)
if h_remaining_if_above >= 0 and not prefers_pop_down then
-- Enough room above the anchor
top = anchor_dimen.y - content_h
elseif h_remaining_if_below >= 0 then
-- Enough room below the anchor
top = anchor_dimen.y + anchor_dimen.h
elseif h_remaining_if_above >= 0 then
-- Enough room above the anchor
top = anchor_dimen.y - content_h
else -- both negative
if h_remaining_if_above >= h_remaining_if_below then
top = 0
else
top = screen_h - content_h
end
end
-- Ensure we show the top if we would overflow
if top < 0 then
top = 0
end
-- Make the initial offsets so that we display at left/top
self._moved_offset_x = left - x
self._moved_offset_y = top - y
end
function MovableContainer:paintTo(bb, x, y)
if self[1] == nil then
return
end
local content_size = self[1]:getSize()
if not self.dimen then
self.dimen = Geom:new{x = 0, y = 0, w = content_size.w, h = content_size.h}
end
self._orig_x = x
self._orig_y = y
-- If there is a widget passed as anchor, we need to set our initial position
-- related to it. After that, we allow it to be moved like any other movable.
if self.anchor and not self._anchor_ensured then
self:ensureAnchor(x, y)
self._anchor_ensured = true
end
-- We just need to shift painting by our _moved_offset_x/y
self.dimen.x = x + self._moved_offset_x
self.dimen.y = y + self._moved_offset_y
if self.alpha then
-- Create/Recreate the compose cache if we changed screen geometry
if not self.compose_bb
or self.compose_bb:getWidth() ~= bb:getWidth()
or self.compose_bb:getHeight() ~= bb:getHeight()
then
if self.compose_bb then
self.compose_bb:free()
end
-- create a canvas for our child widget to paint to
self.compose_bb = Blitbuffer.new(bb:getWidth(), bb:getHeight(), bb:getType())
-- fill it with our usual background color
self.compose_bb:fill(Blitbuffer.COLOR_WHITE)
end
-- now, compose our child widget's content on our canvas
-- NOTE: Unlike AlphaContainer, we aim to support interactive widgets.
-- Most InputContainer-based widgets register their touchzones at paintTo time,
-- and they rely on the target coordinates fed to paintTo for proper on-screen positioning.
-- As such, we have to compose on a target bb sized canvas, at the expected coordinates.
self[1]:paintTo(self.compose_bb, self.dimen.x, self.dimen.y)
-- and finally blit the canvas to the target blitbuffer at the requested opacity level
bb:addblitFrom(self.compose_bb, self.dimen.x, self.dimen.y, self.dimen.x, self.dimen.y, self.dimen.w, self.dimen.h, self.alpha)
else
-- No alpha, just paint
self[1]:paintTo(bb, self.dimen.x, self.dimen.y)
end
end
function MovableContainer:onCloseWidget()
if self.compose_bb then
self.compose_bb:free()
self.compose_bb = nil
end
end
function MovableContainer:_moveBy(dx, dy, restrict_to_screen)
logger.dbg("MovableContainer:_moveBy:", dx, dy)
if dx and dy then
self._moved_offset_x = self._moved_offset_x + Math.round(dx)
self._moved_offset_y = self._moved_offset_y + Math.round(dy)
if restrict_to_screen then
local screen_w, screen_h = Screen:getWidth(), Screen:getHeight()
if self._orig_x + self._moved_offset_x < 0 then
self._moved_offset_x = - self._orig_x
end
if self._orig_y + self._moved_offset_y < 0 then
self._moved_offset_y = - self._orig_y
end
if self._orig_x + self._moved_offset_x + self.dimen.w > screen_w then
self._moved_offset_x = screen_w - self._orig_x - self.dimen.w
end
if self._orig_y + self._moved_offset_y + self.dimen.h > screen_h then
self._moved_offset_y = screen_h - self._orig_y - self.dimen.h
end
end
-- Ensure the offsets are integers, to avoid refresh area glitches
self._moved_offset_x = Math.round(self._moved_offset_x)
self._moved_offset_y = Math.round(self._moved_offset_y)
-- if not restrict_to_screen, we don't need to check anything:
-- we trust gestures' position and distances: if we started with our
-- finger on widget, and moved our finger to screen border, a part
-- of the widget should always be on the screen.
else
-- Not-moving Hold can be used to revert to original position
if self._moved_offset_x == 0 and self._moved_offset_y == 0 then
-- If we hold while already in initial position, take that
-- as a wish to toggle between alpha or no-alpha
if self.alpha then
self.orig_alpha = self.alpha
self.alpha = nil
else
self.alpha = self.orig_alpha or 0.7
-- For testing: to visually see how different alpha
-- values look: loop thru decreasing alpha values
-- self.alpha = self.orig_alpha or 1.0
-- if self.alpha > 0.55 then -- below 0.5 are too transparent
-- self.alpha = self.alpha - 0.1
-- else
-- self.alpha = 0.9
-- end
end
end
self._moved_offset_x = 0
self._moved_offset_y = 0
end
-- We need to have all widgets in the area between orig and move position
-- redraw themselves
local orig_dimen = self.dimen:copy() -- dimen before move/paintTo
UIManager:setDirty("all", function()
local update_region = orig_dimen:combine(self.dimen)
logger.dbg("MovableContainer refresh region", update_region)
return "ui", update_region
end)
end
function MovableContainer:onMovableSwipe(_, ges)
logger.dbg("MovableContainer:onMovableSwipe", ges)
if not self.dimen then -- not yet painted
return false
end
if not ges.pos:intersectWith(self.dimen) then
-- with swipe, ges.pos is swipe's start position, which should
-- be on us to consider it
return false
end
self._moving = false -- could have been set by "pan" event received before "swipe"
local direction = ges.direction
local distance = ges.distance
local sq_distance = math.floor(math.sqrt(distance*distance/2))
-- Use restrict_to_screen for all move with Swipe for easy push to screen
-- borders (user can Hold and pan if he wants them outside)
if direction == "north" then self:_moveBy(0, -distance, true)
elseif direction == "south" then self:_moveBy(0, distance, true)
elseif direction == "east" then self:_moveBy(distance, 0, true)
elseif direction == "west" then self:_moveBy(-distance, 0, true)
elseif direction == "northeast" then self:_moveBy(sq_distance, -sq_distance, true)
elseif direction == "northwest" then self:_moveBy(-sq_distance, -sq_distance, true)
elseif direction == "southeast" then self:_moveBy(sq_distance, sq_distance, true)
elseif direction == "southwest" then self:_moveBy(-sq_distance, sq_distance, true)
end
return true
end
function MovableContainer:onMovableTouch(_, ges)
-- First "pan" event may already be outsise us, we need to
-- remember any "touch" event on us prior to "pan"
logger.dbg("MovableContainer:onMovableTouch", ges)
if not self.dimen then -- not yet painted
return false
end
if ges.pos:intersectWith(self.dimen) then
self._touch_pre_pan_was_inside = true
self._move_relative_x = ges.pos.x
self._move_relative_y = ges.pos.y
else
self._touch_pre_pan_was_inside = false
end
return false
end
function MovableContainer:onMovableHold(_, ges)
logger.dbg("MovableContainer:onMovableHold", ges)
if not self.dimen then -- not yet painted
return false
end
if ges.pos:intersectWith(self.dimen) then
self._moving = true -- start of pan
self._move_relative_x = ges.pos.x
self._move_relative_y = ges.pos.y
return true
end
return false
end
function MovableContainer:onMovableHoldPan(_, ges)
logger.dbg("MovableContainer:onMovableHoldPan", ges)
if not self.dimen then -- not yet painted
return false
end
-- we may sometimes not see the "hold" event
if ges.pos:intersectWith(self.dimen) or self._moving or self._touch_pre_pan_was_inside then
self._touch_pre_pan_was_inside = false -- reset it
self._moving = true
return true
end
return false
end
function MovableContainer:onMovableHoldRelease(_, ges)
logger.dbg("MovableContainer:onMovableHoldRelease", ges)
if not self.dimen then -- not yet painted
return false
end
if self._moving or self._touch_pre_pan_was_inside then
self._moving = false
if not self._move_relative_x or not self._move_relative_y then
-- no previous event gave us accurate move info, ignore it
return false
end
self._move_relative_x = ges.pos.x - self._move_relative_x
self._move_relative_y = ges.pos.y - self._move_relative_y
if math.abs(self._move_relative_x) < self.move_threshold and math.abs(self._move_relative_y) < self.move_threshold then
-- Hold with no move (or less than self.move_threshold): use this to reposition to original position
self:_moveBy()
else
self:_moveBy(self._move_relative_x, self._move_relative_y)
self._move_relative_x = nil
self._move_relative_y = nil
end
return true
end
return false
end
function MovableContainer:onMovablePan(_, ges)
logger.dbg("MovableContainer:onMovablePan", ges)
if not self.dimen then -- not yet painted
return false
end
if ges.pos:intersectWith(self.dimen) or self._moving or self._touch_pre_pan_was_inside then
self._touch_pre_pan_was_inside = false -- reset it
self._moving = true
self._move_relative_x = ges.relative.x
self._move_relative_y = ges.relative.y
return true
end
return false
end
function MovableContainer:onMovablePanRelease(_, ges)
logger.dbg("MovableContainer:onMovablePanRelease", ges)
if not self.dimen then -- not yet painted
return false
end
if self._moving then
self:_moveBy(self._move_relative_x, self._move_relative_y)
self._moving = false
self._move_relative_x = nil
self._move_relative_y = nil
return true
end
return false
end
function MovableContainer:resetEventState()
-- Cancel some internal moving-or-about-to-move state.
-- Can be called explicitely to prevent bad widget interactions.
self._touch_pre_pan_was_inside = false
self._moving = false
end
return MovableContainer