minetest/builtin/fstk/buttonbar.lua

186 lines
5.4 KiB
Lua

--Minetest
--Copyright (C) 2014 sapier
--Copyright (C) 2023 Gregor Parzefall
--
--This program is free software; you can redistribute it and/or modify
--it under the terms of the GNU Lesser General Public License as published by
--the Free Software Foundation; either version 2.1 of the License, or
--(at your option) any later version.
--
--This program is distributed in the hope that it will be useful,
--but WITHOUT ANY WARRANTY; without even the implied warranty of
--MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
--GNU Lesser General Public License for more details.
--
--You should have received a copy of the GNU Lesser General Public License along
--with this program; if not, write to the Free Software Foundation, Inc.,
--51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
local BASE_SPACING = 0.1
local function get_scroll_btn_width()
return core.settings:get_bool("enable_touch") and 0.8 or 0.5
end
local function buttonbar_formspec(self)
if self.hidden then
return ""
end
local formspec = {
"style_type[box;noclip=true]",
string.format("box[%f,%f;%f,%f;%s]", self.pos.x, self.pos.y, self.size.x,
self.size.y, self.bgcolor),
"style_type[box;noclip=false]",
}
local btn_size = self.size.y - 2*BASE_SPACING
-- Spacing works like CSS Flexbox with `justify-content: space-evenly;`.
-- `BASE_SPACING` is used as the minimum spacing, like `gap` in CSS Flexbox.
-- The number of buttons per page is always calculated as if the scroll
-- buttons were visible.
local avail_space = self.size.x - 2*BASE_SPACING - 2*get_scroll_btn_width()
local btns_per_page = math.floor((avail_space - BASE_SPACING) / (btn_size + BASE_SPACING))
self.num_pages = math.ceil(#self.buttons / btns_per_page)
self.cur_page = math.min(self.cur_page, self.num_pages)
local first_btn = (self.cur_page - 1) * btns_per_page + 1
local show_scroll_btns = self.num_pages > 1
-- In contrast, the button spacing calculation takes hidden scroll buttons
-- into account.
local real_avail_space = show_scroll_btns and avail_space or self.size.x
local btn_spacing = (real_avail_space - btns_per_page * btn_size) / (btns_per_page + 1)
local btn_start_x = self.pos.x + btn_spacing
if show_scroll_btns then
btn_start_x = btn_start_x + BASE_SPACING + get_scroll_btn_width()
end
for i = first_btn, first_btn + btns_per_page - 1 do
local btn = self.buttons[i]
if btn == nil then
break
end
local btn_pos = {
x = btn_start_x + (i - first_btn) * (btn_size + btn_spacing),
y = self.pos.y + BASE_SPACING,
}
table.insert(formspec, string.format("image_button[%f,%f;%f,%f;%s;%s;%s;true;false]tooltip[%s;%s]",
btn_pos.x, btn_pos.y, btn_size, btn_size, btn.image, btn.name,
btn.caption, btn.name, btn.tooltip))
end
if show_scroll_btns then
local btn_prev_pos = {
x = self.pos.x + BASE_SPACING,
y = self.pos.y + BASE_SPACING,
}
local btn_next_pos = {
x = self.pos.x + self.size.x - BASE_SPACING - get_scroll_btn_width(),
y = self.pos.y + BASE_SPACING,
}
table.insert(formspec, string.format("style[%s,%s;noclip=true]",
self.btn_prev_name, self.btn_next_name))
table.insert(formspec, string.format("button[%f,%f;%f,%f;%s;<]",
btn_prev_pos.x, btn_prev_pos.y, get_scroll_btn_width(), btn_size,
self.btn_prev_name))
table.insert(formspec, string.format("button[%f,%f;%f,%f;%s;>]",
btn_next_pos.x, btn_next_pos.y, get_scroll_btn_width(), btn_size,
self.btn_next_name))
end
return table.concat(formspec)
end
local function buttonbar_buttonhandler(self, fields)
if fields[self.btn_prev_name] then
if self.cur_page > 1 then
self.cur_page = self.cur_page - 1
return true
elseif self.cur_page == 1 then
self.cur_page = self.num_pages
return true
end
end
if fields[self.btn_next_name] then
if self.cur_page < self.num_pages then
self.cur_page = self.cur_page + 1
return true
elseif self.cur_page == self.num_pages then
self.cur_page = 1
return true
end
end
for _, btn in ipairs(self.buttons) do
if fields[btn.name] then
return self.userbuttonhandler(fields)
end
end
end
local buttonbar_metatable = {
handle_buttons = buttonbar_buttonhandler,
handle_events = function(self, event) end,
get_formspec = buttonbar_formspec,
hide = function(self) self.hidden = true end,
show = function(self) self.hidden = false end,
delete = function(self) ui.delete(self) end,
add_button = function(self, name, caption, image, tooltip)
if caption == nil then caption = "" end
if image == nil then image = "" end
if tooltip == nil then tooltip = "" end
table.insert(self.buttons, {
name = name,
caption = caption,
image = image,
tooltip = tooltip,
})
end,
}
buttonbar_metatable.__index = buttonbar_metatable
function buttonbar_create(name, pos, size, bgcolor, cbf_buttonhandler)
assert(type(name) == "string" )
assert(type(pos) == "table" )
assert(type(size) == "table" )
assert(type(bgcolor) == "string" )
assert(type(cbf_buttonhandler) == "function")
local self = {}
self.type = "addon"
self.name = name
self.pos = pos
self.size = size
self.bgcolor = bgcolor
self.userbuttonhandler = cbf_buttonhandler
self.hidden = false
self.buttons = {}
self.num_pages = 1
self.cur_page = 1
self.btn_prev_name = "btnbar_prev_" .. self.name
self.btn_next_name = "btnbar_next_" .. self.name
setmetatable(self, buttonbar_metatable)
ui.add(self)
return self
end