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TextBoxWidget:getFontSizeToFitHeight(): allow for more accuracy

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By providing the font that will be used.
As it's more expensive, use only when really needed.
This commit is contained in:
poire-z
2023-05-11 20:23:39 +02:00
parent 552787db89
commit 4fa7e718a2
1 changed files with 27 additions and 1 deletions
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28
frontend/ui/widget/textboxwidget.lua
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@@ -1084,7 +1084,7 @@ function TextBoxWidget:getVisibleHeightRatios()
end
-- Helper function to be used before intanstiating a TextBoxWidget instance
function TextBoxWidget:getFontSizeToFitHeight(height_px, nb_lines, line_height_em)
function TextBoxWidget:getFontSizeToFitHeight(height_px, nb_lines, line_height_em, font_face, font_bold)
-- Get a font size that would fit nb_lines in height_px.
-- A font with the returned size should then be provided
-- to TextBoxWidget:new() (as well as the line_height_em given
@@ -1102,6 +1102,32 @@ function TextBoxWidget:getFontSizeToFitHeight(height_px, nb_lines, line_height_e
if Screen:scaleBySize(font_size) > face_size then -- be really sure we won't get it larger
font_size = font_size - 1
end
-- Because of self.line_glyph_extra_height added to the final bb, the font_size we got
-- up to here can still generate a TextBoxWidget taller than the provided height_px,
-- which might be good enough for some usages.
-- If better accuracy is needed, provide (..., font_face, font_bold) so we can return
-- a better font_size for the font that will be used.
if font_face then
while true do
-- As done in TextBoxWidget:init():
local line_height_px = Math.round( (1 + line_height_em) * Screen:scaleBySize(font_size) )
local face = Font:getFace(font_face, font_size)
face = Font:getAdjustedFace(face, font_bold)
local face_height = face.ftface:getHeightAndAscender()
local line_heights_diff = math.floor(line_height_px - face_height)
if line_heights_diff >= 0 then
break
end
local line_glyph_extra_height = -line_heights_diff
if line_height_px * nb_lines + line_glyph_extra_height <= height_px then
break
end
if font_size <= 1 then
break
end
font_size = font_size - 1
end
end
return font_size
end