Merge pull request #931 from hwhw/master

alpha-blitting widget and a few fixes

frontend/ui/rendertext.lua

@@ -163,11 +163,11 @@ function RenderText:renderUtf8Text(buffer, x, y, face, text, kerning, bold, bgco
             if kerning and (prevcharcode ~= 0) then
                 pen_x = pen_x + face.ftface:getKerning(prevcharcode, charcode)
             end
-            buffer:addblitFrom(
+            buffer:blitFrom(
                 glyph.bb,
                 x + pen_x + glyph.l, y - glyph.t,
                 0, 0,
-                glyph.bb:getWidth(), glyph.bb:getHeight(), 1)
+                glyph.bb:getWidth(), glyph.bb:getHeight())
             pen_x = pen_x + glyph.ax
             prevcharcode = charcode
         end -- if pen_x < text_width

frontend/ui/widget/container/alphacontainer.lua

@@ -0,0 +1,54 @@
+local WidgetContainer = require("ui/widget/container/widgetcontainer")
+local BlitBuffer = require("ffi/blitbuffer")
+
+--[[
+AlphaContainer will paint its content (1 widget) onto lower levels using
+a transparency (0..1)
+--]]
+local AlphaContainer = WidgetContainer:new{
+    alpha = 1,
+    -- we cache a blitbuffer object for re-use here:
+    private_bb = nil,
+    -- we save the underlying area here:
+    background_bb = nil,
+    background_bb_x = nil,
+    background_bb_y = nil
+}
+
+function AlphaContainer:paintTo(bb, x, y)
+    local contentSize = self[1]:getSize()
+    local private_bb = self.private_bb
+
+    if self.background_bb then
+        -- we have a saved copy of what was below our paint area
+        -- we restore this first
+        bb:blitFrom(self.background_bb, self.background_bb_x, self.background_bb_y)
+    end
+
+    if not private_bb
+    or private_bb:getWidth() ~= contentSize.w
+    or private_bb:getHeight() ~= contentSize.h
+    then
+        -- create private blitbuffer for our child widget to paint to
+        private_bb = BlitBuffer.new(contentSize.w, contentSize.h, bb:getType())
+        self.private_bb = private_bb
+
+        -- save what is below our painting area
+        if not self.background_bb
+        or self.background_bb:getWidth() ~= contentSize.w
+        or self.background_bb:getHeight() ~= contentSize.h
+        then
+            self.background_bb = BlitBuffer.new(contentSize.w, contentSize.h, bb:getType())
+        end
+        self.background_bb:blitFrom(bb, 0, 0, x, y)
+    end
+
+    -- now have our childs paint to the private blitbuffer
+    -- TODO: should we clean before painting?
+    self[1]:paintTo(private_bb, 0, 0)
+
+    -- blit the private blitbuffer to our parent blitbuffer
+    bb:addblitFrom(private_bb, x, y, nil, nil, nil, nil, self.alpha)
+end
+
+return AlphaContainer

wtest.lua

@@ -22,10 +22,12 @@ local Font = require("ui/font")
 local Geom = require("ui/geometry")
 local Menu = require("ui/widget/menu")
 local Widget = require("ui/widget/widget")
+local TextWidget = require("ui/widget/textwidget")
 local InfoMessage = require("ui/widget/infomessage")
 local InputContainer = require("ui/widget/container/inputcontainer")
 local CenterContainer = require("ui/widget/container/centercontainer")
 local FrameContainer = require("ui/widget/container/framecontainer")
+local AlphaContainer = require("ui/widget/container/alphacontainer")
 local ConfirmBox = require("ui/widget/confirmbox")
 local TouchMenu = require("ui/widget/touchmenu")
 local InputText = require("ui/widget/inputtext")
@@ -163,16 +165,20 @@ end
 -----------------------------------------------------
 -- example widget: a clock
 -----------------------------------------------------
-Clock = FrameContainer:new{
-    background = 0,
-    bordersize = 1,
-    margin = 0,
-    padding = 1
+Clock = AlphaContainer:new{
+    alpha = 0.7,
+
+    FrameContainer:new{
+        background = 0,
+        bordersize = 1,
+        margin = 0,
+        padding = 1
+    }
 }
 
 function Clock:schedFunc()
-    self[1]:free()
-    self[1] = self:getTextWidget()
+    self[1][1]:free()
+    self[1][1] = self:getTextWidget()
     UIManager:setDirty(self)
     -- reschedule
     -- TODO: wait until next real second shift
@@ -180,7 +186,7 @@ function Clock:schedFunc()
 end
 
 function Clock:onShow()
-    self[1] = self:getTextWidget()
+    self[1][1] = self:getTextWidget()
     self:schedFunc()
 end
 
@@ -341,10 +347,10 @@ inputtext = InputText:new{
 -----------------------------------------------------------------------
 -- you may want to uncomment following show calls to see the changes
 -----------------------------------------------------------------------
-UIManager:show(Background:new())
+--UIManager:show(Background:new())
 -- UIManager:show(TestGrid)
 UIManager:show(TestVisible)
---UIManager:show(Clock:new())
+UIManager:show(Clock:new())
 --UIManager:show(M)
 --UIManager:show(Quiz)
 --UIManager:show(readerwindow)