koreader/frontend/ui/widget/buttondialog.lua

--[[--
A button dialog widget that shows a grid of buttons.

    @usage
    local button_dialog = ButtonDialog:new{
        buttons = {
            {
                {
                    text = "First row, left side",
                    callback = function() end,
                    hold_callback = function() end
                },
                {
                    text = "First row, middle",
                    callback = function() end
                },
                {
                    text = "First row, right side",
                    callback = function() end
                }
            },
            {
                {
                    text = "Second row, full span",
                    callback = function() end
                }
            },
            {
                {
                    text = "Third row, left side",
                    callback = function() end
                },
                {
                    text = "Third row, right side",
                    callback = function() end
                }
            }
        }
    }
--]]

local Blitbuffer = require("ffi/blitbuffer")
local ButtonTable = require("ui/widget/buttontable")
local CenterContainer = require("ui/widget/container/centercontainer")
local Device = require("device")
local FrameContainer = require("ui/widget/container/framecontainer")
local Geom = require("ui/geometry")
local GestureRange = require("ui/gesturerange")
local InputContainer = require("ui/widget/container/inputcontainer")
local MovableContainer = require("ui/widget/container/movablecontainer")
local ScrollableContainer = require("ui/widget/container/scrollablecontainer")
local Size = require("ui/size")
local UIManager = require("ui/uimanager")
local VerticalGroup = require("ui/widget/verticalgroup")
local VerticalSpan = require("ui/widget/verticalspan")
local _ = require("gettext")
local Screen = require("device").screen

local ButtonDialog = InputContainer:extend{
    buttons = nil,
    width = nil,
    width_factor = nil, -- number between 0 and 1, factor to the smallest of screen width and height
    shrink_unneeded_width = false, -- have 'width' meaning 'max_width'
    shrink_min_width = nil, -- default to ButtonTable's default
    tap_close_callback = nil,
    alpha = nil, -- passed to MovableContainer
    -- If scrolling, prefers using this/these numbers of buttons rows per page
    -- (depending on what the screen height allows) to compute the height.
    rows_per_page = nil, -- number or array of numbers
}

function ButtonDialog:init()
    if not self.width then
        if not self.width_factor then
            self.width_factor = 0.9 -- default if no width specified
        end
        self.width = math.floor(math.min(Screen:getWidth(), Screen:getHeight()) * self.width_factor)
    end
    if Device:hasKeys() then
        local close_keys = Device:hasFewKeys() and { "Back", "Left" } or Device.input.group.Back
        self.key_events.Close = { { close_keys } }
    end
    if Device:isTouchDevice() then
        self.ges_events.TapClose = {
            GestureRange:new{
                ges = "tap",
                range = Geom:new{
                    x = 0, y = 0,
                    w = Screen:getWidth(),
                    h = Screen:getHeight(),
                }
            }
        }
    end
    self.buttontable = ButtonTable:new{
        buttons = self.buttons,
        width = self.width - 2*Size.border.window - 2*Size.padding.button,
        shrink_unneeded_width = self.shrink_unneeded_width,
        shrink_min_width = self.shrink_min_width,
        show_parent = self,
    }
    -- If the ButtonTable ends up being taller than the screen, wrap it inside a ScrollableContainer.
    -- Ensure some small top and bottom padding, so the scrollbar stand out, and some outer margin
    -- so the this dialog does not take the full height and stand as a popup.
    local max_height = Screen:getHeight() - 2*Size.padding.buttontable - 2*Size.margin.default
    local height = self.buttontable:getSize().h
    local scontainer
    if height > max_height then
        -- Adjust the ScrollableContainer to an integer multiple of the row height
        -- (assuming all rows get the same height), so when scrolling per page,
        -- we always end up seeing full rows.
        self.buttontable:setupGridScrollBehaviour()
        local step_scroll_grid = self.buttontable:getStepScrollGrid()
        local row_height = step_scroll_grid[1].bottom + 1 - step_scroll_grid[1].top
        local fit_rows = math.floor(max_height / row_height)
        if self.rows_per_page then
            if type(self.rows_per_page) == "number" then
                if fit_rows > self.rows_per_page then
                    fit_rows = self.rows_per_page
                end
            else
                for _, nb in ipairs(self.rows_per_page) do
                    if fit_rows >= nb then
                        fit_rows = nb
                        break
                    end
                end
            end
        end
        -- (Comment the next line to test ScrollableContainer behaviour when things do not fit)
        max_height = row_height * fit_rows
        self.cropping_widget = ScrollableContainer:new{
            dimen = Geom:new{
                -- We'll be exceeding the provided width in this case (let's not bother
                -- ensuring it, we'd need to re-setup the ButtonTable...)
                w = self.buttontable:getSize().w + ScrollableContainer:getScrollbarWidth(),
                h = max_height,
            },
            show_parent = self,
            step_scroll_grid = step_scroll_grid,
            self.buttontable,
        }
        scontainer = VerticalGroup:new{
            VerticalSpan:new{ width=Size.padding.buttontable },
            self.cropping_widget,
            VerticalSpan:new{ width=Size.padding.buttontable },
        }
    end
    self.movable = MovableContainer:new{
            alpha = self.alpha,
            anchor = self.anchor,
            FrameContainer:new{
                scontainer or self.buttontable,
                background = Blitbuffer.COLOR_WHITE,
                bordersize = Size.border.window,
                radius = Size.radius.window,
                padding = Size.padding.button,
                -- No padding at top or bottom to make all buttons
                -- look the same size
                padding_top = 0,
                padding_bottom = 0,
            }
    }

    self[1] = CenterContainer:new{
        dimen = Screen:getSize(),
        self.movable,
    }
end

function ButtonDialog:getButtonById(id)
    return self.buttontable:getButtonById(id)
end

function ButtonDialog:getScrolledOffset()
    if self.cropping_widget then
        return self.cropping_widget:getScrolledOffset()
    end
end

function ButtonDialog:setScrolledOffset(offset_point)
    if offset_point and self.cropping_widget then
        return self.cropping_widget:setScrolledOffset(offset_point)
    end
end

function ButtonDialog:onShow()
    UIManager:setDirty(self, function()
        return "ui", self.movable.dimen
    end)
end

function ButtonDialog:onCloseWidget()
    UIManager:setDirty(nil, function()
        return "flashui", self.movable.dimen
    end)
end

function ButtonDialog:onTapClose()
    UIManager:close(self)
    if self.tap_close_callback then
        self.tap_close_callback()
    end
    return true
end

function ButtonDialog:onClose()
    self:onTapClose()
    return true
end

function ButtonDialog:paintTo(...)
    InputContainer.paintTo(self, ...)
    self.dimen = self.movable.dimen
end

return ButtonDialog