Merge pull request #535 from psychon/textbox_preferred_size

Add functions for querying a textbox's preferred size

Closes https://github.com/awesomeWM/awesome/pull/535.

lib/awful/tooltip.lua

@@ -71,9 +71,8 @@ end
 -- @tparam tooltip self A tooltip object.
 local function set_geometry(self)
     local my_geo = self.wibox:geometry()
-    local textbox_context = {dpi=beautiful.xresources.get_dpi(mouse.screen)}
     -- calculate width / height
-    local n_w, n_h = self.textbox:fit(textbox_context, -1, -1) -- Hack! :(
+    local n_w, n_h = self.textbox:get_preferred_size(mouse.screen)
     n_w = n_w + self.marginbox.left + self.marginbox.right
     n_h = n_h + self.marginbox.top + self.marginbox.bottom
     if my_geo.width ~= n_w or my_geo.height ~= n_h then

lib/naughty/core.lua

@@ -458,8 +458,6 @@ function naughty.notify(args)
     local border_color = args.border_color or preset.border_color or beautiful.bg_focus or '#535d6c'
     local notification = { screen = screen, destroy_cb = destroy_cb, timeout = timeout }
 
-    local textbox_context = {dpi=bt.xresources.get_dpi(s)}
-
     -- replace notification if needed
     if args.replaces_id then
         local obj = naughty.getById(args.replaces_id)
@@ -532,7 +530,7 @@ function naughty.notify(args)
             actiontextbox:set_font(font)
             actiontextbox:set_markup(string.format('<b>%s</b>', action))
             -- calculate the height and width
-            local w, h = actiontextbox:fit(textbox_context, -1, -1) -- Hack! :(
+            local w, h = actiontextbox:get_preferred_size(s)
             local height = h + 2 * margin
             local width = w + 2 * margin
 
@@ -600,9 +598,20 @@ function naughty.notify(args)
 
     if hover_timeout then notification.box:connect_signal("mouse::enter", hover_destroy) end
 
+    -- calculate the width
+    if not width then
+        local w, h = textbox:get_preferred_size(s)
+        width = w + (iconbox and icon_w + 2 * margin or 0) + 2 * margin
+    end
+
+    if width < actions_max_width then
+        width = actions_max_width
+    end
+
     -- calculate the height
     if not height then
-        local w, h = textbox:fit(textbox_context, -1, -1) -- Hack! :-(
+        local w = width - (iconbox and icon_w + 2 * margin or 0) - 2 * margin
+        local h = textbox:get_height_for_width(w, s)
         if iconbox and icon_h + 2 * margin > h + 2 * margin then
             height = icon_h + 2 * margin
         else
@@ -612,16 +621,6 @@ function naughty.notify(args)
 
     height = height + actions_total_height
 
-    -- calculate the width
-    if not width then
-        local w, h = textbox:fit(textbox_context, -1, -1) -- Hack! :-(
-        width = w + (iconbox and icon_w + 2 * margin or 0) + 2 * margin
-    end
-
-    if width < actions_max_width then
-        width = actions_max_width
-    end
-
     -- crop to workarea size if too big
     local workarea = capi.screen[screen].workarea
     if width > workarea.width - 2 * (border_width or 0) - 2 * (naughty.config.padding or 0) then

lib/wibox/widget/textbox.lua

@@ -19,11 +19,8 @@ local error = error
 
 local textbox = { mt = {} }
 
---- Setup a pango layout for the given textbox and cairo context
+--- Set the DPI of a Pango layout
-local function setup_layout(box, width, height, dpi)
+local function setup_dpi(box, dpi)
-    local layout = box._layout
-    layout.width = Pango.units_from_double(width)
-    layout.height = Pango.units_from_double(height)
     if box.dpi ~= dpi then
         box.dpi = dpi
         box._ctx:set_resolution(dpi)
@@ -31,6 +28,13 @@ local function setup_layout(box, width, height, dpi)
     end
 end
 
+--- Setup a pango layout for the given textbox and dpi
+local function setup_layout(box, width, height, dpi)
+    box._layout.width = Pango.units_from_double(width)
+    box._layout.height = Pango.units_from_double(height)
+    setup_dpi(box, dpi)
+end
+
 --- Draw the given textbox on the given cairo context in the given geometry
 function textbox:draw(context, cr, width, height)
     setup_layout(self, width, height, context.dpi)
@@ -46,18 +50,69 @@ function textbox:draw(context, cr, width, height)
     cr:show_layout(self._layout)
 end
 
---- Fit the given textbox
+local function do_fit_return(self)
-function textbox:fit(context, width, height)
-    setup_layout(self, width, height, context.dpi)
     local ink, logical = self._layout:get_pixel_extents()
-
     if logical.width == 0 or logical.height == 0 then
         return 0, 0
     end
-
     return logical.width, logical.height
 end
 
+--- Fit the given textbox
+function textbox:fit(context, width, height)
+    setup_layout(self, width, height, context.dpi)
+    return do_fit_return(self)
+end
+
+--- Get the preferred size of a textbox.
+-- This returns the size that the textbox would use if infinite space were
+-- available.
+-- @tparam integer s The screen number on which the textbox will be displayed.
+-- @treturn number The preferred width.
+-- @treturn number The preferred height.
+function textbox:get_preferred_size(s)
+    return self:get_preferred_size_at_dpi(beautiful.xresources.get_dpi(s))
+end
+
+--- Get the preferred height of a textbox at a given width.
+-- This returns the height that the textbox would use when it is limited to the
+-- given width.
+-- @tparam number width The available width.
+-- @tparam integer s The screen number on which the textbox will be displayed.
+-- @treturn number The needed height.
+function textbox:get_height_for_width(width, s)
+    return self:get_height_for_width_at_dpi(width, beautiful.xresources.get_dpi(s))
+end
+
+--- Get the preferred size of a textbox.
+-- This returns the size that the textbox would use if infinite space were
+-- available.
+-- @tparam number dpi The DPI value to render at.
+-- @treturn number The preferred width.
+-- @treturn number The preferred height.
+function textbox:get_preferred_size_at_dpi(dpi)
+    local max_lines = 2^20
+    setup_dpi(self, dpi)
+    self._layout.width = -1 -- no width set
+    self._layout.height = -max_lines -- show this many lines per paragraph
+    return do_fit_return(self)
+end
+
+--- Get the preferred height of a textbox at a given width.
+-- This returns the height that the textbox would use when it is limited to the
+-- given width.
+-- @tparam number width The available width.
+-- @tparam number dpi The DPI value to render at.
+-- @treturn number The needed height.
+function textbox:get_height_for_width_at_dpi(width, dpi)
+    local max_lines = 2^20
+    setup_dpi(self, dpi)
+    self._layout.width = Pango.units_from_double(width)
+    self._layout.height = -max_lines -- show this many lines per paragraph
+    local w, h = do_fit_return(self)
+    return h
+end
+
 --- Set the text of the textbox (with
 -- [Pango markup](https://developer.gnome.org/pango/stable/PangoMarkupFormat.html)).
 -- @tparam string text The text to set. This can contain pango markup (e.g.