Scrolling improvements, fixes #13

example/main.lua

@@ -29,12 +29,16 @@ layout.mainCanvas.text = [[
 This program demonstrates some features of the Luigi UI library.
 
 Luigi is a widget toolkit that runs under Love or LuaJIT.
-]]
+
+Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.]]
+
 
 layout.mainCanvas.align = 'top'
 
 layout.mainCanvas.wrap = true
 
+layout.mainCanvas.scroll = true
+
 -- help dialogs
 
 layout.about:onPress(function()

luigi/backend/ffisdl/font.lua

@@ -245,20 +245,4 @@ function Font:getAdvance (text)
     return w[0]
 end
 
-function Font:getWrappedHeight (text)
-    --[[
-    -- TTF_Font *font, const char *text, int wrapLength, int *w, int *h, int *lineCount
-    local w, h, lineCount = IntOut(), IntOut(), IntOut()
-
-    SDL2_ttf.TTF_SizeUTF8_Wrapped(self.sdlFont, text, self.width,
-        w, h, lineCount)
-
-    return self:getLineHeight() * lineCount
-    --]]
-
-    local w, h = IntOut(), IntOut()
-    SDL2_ttf.TTF_SizeUTF8(self.sdlFont, text, w, h)
-    return h[0]
-end
-
 return Font

luigi/backend/ffisdl/text.lua

@@ -77,7 +77,7 @@ local function renderMulti (self, font, text, color, align, limit)
         sdl.setTextureAlphaMod(self.sdlTexture, alphaMod)
     end
 
-    self.width, self.height = surface.w, surface.h
+    self.width, self.height = limit, height
 end
 
 function Text:constructor (renderer, font, text, color, align, limit)

luigi/backend/love/font.lua

@@ -50,16 +50,4 @@ function Font:getAdvance (text)
     return (self.loveFont:getWidth(text))
 end
 
-if love._version_minor < 10 then
-    function Font:getWrappedHeight (text)
-        local _, lines = self.loveFont:getWrap(text, self.width)
-        return lines * self.loveFont:getHeight()
-    end
-else
-    function Font:getWrappedHeight (text)
-        local _, lines = self.loveFont:getWrap(text, self.width)
-        return #lines * self.loveFont:getHeight()
-    end
-end
-
 return Font

luigi/layout.lua

@@ -56,6 +56,8 @@ function Layout:constructor (data, master)
     self.root = data
 
     Widget(self, data)
+
+    self.isReady = true
 end
 
 local function clearWidget (widget)
@@ -321,24 +323,7 @@ function Layout:addDefaultHandlers ()
     self:onWheelMove(function (event)
         if not event.hit then return end
         for widget in event.target:eachAncestor(true) do
-            if widget.scroll then
+            if widget:scrollBy(nil, event.y) then return false end
-                if not widget.scrollY then
-                    widget.scrollY = 0
-                end
-                local scrollY = widget.scrollY - event.y * 10
-                local maxY = widget:getContentHeight() - widget:getHeight()
-                if scrollY > maxY then
-                    scrollY = maxY
-                end
-                if scrollY < 0 then
-                    scrollY = 0
-                end
-                if scrollY ~= widget.scrollY then
-                    widget.scrollY = scrollY
-                    widget:reshape()
-                    return false
-                end
-            end -- if widget.scroll
         end -- ancestor loop
         return false
     end) -- wheel move

luigi/painter.lua

@@ -267,7 +267,9 @@ function Painter:paintIconAndText ()
 
     -- draw the text
     if text and textX and textY and w > 1 then
-        textX, textY = math.floor(textX), math.floor(textY)
+        widget.innerHeight = textY - y + widget.textData:getHeight()
+        textX = math.floor(textX - (widget.scrollX or 0))
+        textY = math.floor(textY - (widget.scrollY or 0))
         Backend.draw(widget.textData, textX, textY)
     end
 

luigi/widget.lua

@@ -43,9 +43,10 @@ the `Input` class, and should generally be treated as read-only.
 Widget.hovered = false
 
 --[[--
-Whether the pointer was pressed on this widget and not yet released.
+Table of mouse buttons pressed on this widget and not yet released,
+keyed by mouse button name with booleans as values.
 
-Can be used by styles and themes. This value is automatically set by
+Can be used by styles and themes. Values are automatically set by
 the `Input` class, and should generally be treated as read-only.
 --]]--
 Widget.pressed = nil
@@ -614,9 +615,16 @@ Gets the combined width of the widget's children.
 The content width.
 --]]--
 function Widget:getContentWidth ()
+    if not self.layout.isReady then return 0 end
     local width = 0
-    for _, child in ipairs(self) do
+    if self.flow == 'x' then
-        width = width + child:getWidth()
+        for _, child in ipairs(self) do
+            width = width + child:getWidth()
+        end
+    else
+        for _, child in ipairs(self) do
+            width = math.max(width, child:getWidth())
+        end
     end
     return width
 end
@@ -630,9 +638,16 @@ Gets the combined height of the widget's children.
 The content height.
 --]]--
 function Widget:getContentHeight ()
+    if not self.layout.isReady then return 0 end
     local height = 0
-    for _, child in ipairs(self) do
+    if self.flow ~= 'x' then
-        height = height + child:getHeight()
+        for _, child in ipairs(self) do
+            height = height + child:getHeight()
+        end
+    else
+        for _, child in ipairs(self) do
+            height = math.max(height, child:getHeight())
+        end
     end
     return height
 end
@@ -738,21 +753,39 @@ fires a Reshape event (does not bubble). Called recursively for each child.
 When setting a widget's width or height, this function is automatically called
 on the parent widget.
 --]]--
-function Widget:reshape ()
+function Widget:reshape (keepText)
     if self.isReshaping then return end
     self.isReshaping = true
 
+    self:scrollBy(0, 0)
+
     self.position = {}
     self.dimensions = {}
 
-    self.textData = nil
+    if not keepText then self.textData = nil end
+
     Event.Reshape:emit(self, { target = self })
     for i, widget in ipairs(self) do
         if widget.reshape then
-            widget:reshape()
+            widget:reshape(keepText)
         end
     end
     self.isReshaping = nil
 end
 
+function Widget:scrollBy (x, y)
+    if not self.scroll then return end
+    if not self.scrollY then self.scrollY = 0 end
+    local scrollY = self.scrollY - y * 10
+    local inner = math.max(self:getContentHeight(), self.innerHeight or 0)
+    local maxY = inner - self:getHeight()
+        + (self.padding or 0) * 2 + (self.margin or 0) * 2
+    scrollY = math.max(math.min(scrollY, maxY), 0)
+    if scrollY ~= self.scrollY then
+        self.scrollY = scrollY
+        self:reshape(true)
+        return true
+    end
+end
+
 return setmetatable(Widget, { __call = metaCall })