refactor(pagebuilders): Move grid pagebuilder to first class module

sile-typesetter · Dec 10, 2022 · 1e171ec · 1e171ec
1 parent f4ad240
commit 1e171ec
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Showing 2 changed files with 75 additions and 72 deletions.
diff --git a/packages/grid/init.lua b/packages/grid/init.lua
@@ -3,6 +3,8 @@ local base = require("packages.base")
 local package = pl.class(base)
 package._name = "grid"
 
+local oldPagebuilderType, oldTypesetterType
+
 local function startGridInFrame (typesetter)
   if not SILE.typesetter.state.grid then return end -- Ensure the frame hook isn't effective when grid is off
   local queue = typesetter.state.outputQueue
@@ -20,73 +22,6 @@ local function startGridInFrame (typesetter)
   end
 end
 
-local gridPagebuilder = pl.class(SILE.pagebuilders.base)
-gridPagebuilder._name = "grid"
-
-function gridPagebuilder:_init()
-  SILE.pagebuilders.base._init()
-end
-
-function gridPagebuilder.findBestBreak (_, options)
-  local vboxlist = SU.required(options, "vboxlist", "in findBestBreak")
-  local target   = SU.required(options, "target", "in findBestBreak")
-  local i = 0
-  local totalHeight = SILE.length()
-  local bestBreak = 0
-  SU.debug("pagebuilder", "Page builder for frame", SILE.typesetter.frame.id, "called with", #vboxlist, "nodes,", target)
-  if SU.debugging("vboxes") then
-    for j, box in ipairs(vboxlist) do
-      SU.debug("vboxes", (j == i and " >" or "  ") .. j .. ": " .. box)
-    end
-  end
-  while i < #vboxlist do
-    i = i + 1
-    if not vboxlist[i].is_vglue then
-      i = i - 1
-      break
-    end
-  end
-  while i < #vboxlist do
-    i = i + 1
-    local node = vboxlist[i]
-    SU.debug("pagebuilder", "Dealing with VBox", node)
-    if node.is_vbox then
-      totalHeight = totalHeight + node.height:absolute() + node.depth:absolute()
-    elseif node.is_vglue then
-      totalHeight = totalHeight + node.height:absolute()
-    elseif node.is_insertion then
-      -- TODO: refactor as hook and without side effects!
-      target = SILE.insertions.processInsertion(vboxlist, i, totalHeight, target)
-      node = vboxlist[i]
-    end
-    local left = target - totalHeight
-    local _left = left:tonumber()
-    SU.debug("pagebuilder", "I have", left, "left")
-    SU.debug("pagebuilder", "totalHeight", totalHeight, "with target", target)
-    local badness = 0
-    if _left < 0 then badness = 1000000 end
-    if node.is_penalty then
-      if node.penalty < -3000 then badness = 100000
-      else badness = -_left * _left - node.penalty
-      end
-    end
-    if badness > 0 then
-      local onepage = {}
-      for j = 1, bestBreak do
-        onepage[j] = table.remove(vboxlist, 1)
-      end
-      while #onepage > 1 and onepage[#onepage].discardable do
-        onepage[#onepage] = nil
-      end
-      return onepage, 1000
-    end
-    bestBreak = i
-  end
-  return false, false
-end
-
-local oldPageBuilder, oldLeadingFor, oldPushVglue, oldPushExplicitVglue
-
 function package:_init (options)
   self.options = options or {}
   self.options.spacing = SILE.measurement(self.options.spacing or "1bs")
@@ -109,13 +44,13 @@ function package:registerCommands ()
     SILE.typesetter:registerNewFrameHook(debugGrid)
   end)
 
-  -- TODO: save original typsetter and pagebuilter class types, recast them
-  -- to the original types instead of assuming defaults when disabling grid
   self:registerCommand("grid", function (options, _)
     local spacing = SU.cast("measurement", options.spacing or self.options.spacing)
     SILE.typesetter.state.grid = true
     self.options.spacing = SILE.parseComplexFrameDimension(spacing)
-    gridPagebuilder:cast(SILE.pagebuilder)
+    oldPagebuilderType = SILE.pagebuilder._name
+    oldTypesetterType = SILE.typesetter._name
+    SILE.pagebuilders.grid:cast(SILE.pagebuilder)
     SILE.typesetters.grid:cast(SILE.typesetter)
     SILE.typesetter.options = { spacing = self.options.spacing }
     if SILE.typesetter.frame then
@@ -126,8 +61,8 @@ function package:registerCommands ()
 
   self:registerCommand("no-grid", function (_, _)
     SILE.typesetter.state.grid = false
-    SILE.typesetters.base:cast(SILE.typesetter)
-    SILE.pagebuilders.base:cast(pagebuilder)
+    SILE.typesetters[oldTypesetterType]:cast(SILE.typesetter)
+    SILE.pagebuilders[oldPagebuilderType]:cast(SILE.pagebuilder)
   end, "Stops grid typesetting.")
 
 end

diff --git a/pagebuilders/grid.lua b/pagebuilders/grid.lua
@@ -0,0 +1,68 @@
+local base = require("pagebuilders.base")
+
+local pagebuilder = pl.class(base)
+pagebuilder._name = "grid"
+
+function pagebuilder:_init()
+  base._init(self)
+end
+
+function pagebuilder.findBestBreak (_, options)
+  local vboxlist = SU.required(options, "vboxlist", "in findBestBreak")
+  local target   = SU.required(options, "target", "in findBestBreak")
+  local i = 0
+  local totalHeight = SILE.length()
+  local bestBreak = 0
+  SU.debug("pagebuilder", "Page builder for frame", SILE.typesetter.frame.id, "called with", #vboxlist, "nodes,", target)
+  if SU.debugging("vboxes") then
+    for j, box in ipairs(vboxlist) do
+      SU.debug("vboxes", (j == i and " >" or "  ") .. j .. ": " .. box)
+    end
+  end
+  while i < #vboxlist do
+    i = i + 1
+    if not vboxlist[i].is_vglue then
+      i = i - 1
+      break
+    end
+  end
+  while i < #vboxlist do
+    i = i + 1
+    local node = vboxlist[i]
+    SU.debug("pagebuilder", "Dealing with VBox", node)
+    if node.is_vbox then
+      totalHeight = totalHeight + node.height:absolute() + node.depth:absolute()
+    elseif node.is_vglue then
+      totalHeight = totalHeight + node.height:absolute()
+    elseif node.is_insertion then
+      -- TODO: refactor as hook and without side effects!
+      target = SILE.insertions.processInsertion(vboxlist, i, totalHeight, target)
+      node = vboxlist[i]
+    end
+    local left = target - totalHeight
+    local _left = left:tonumber()
+    SU.debug("pagebuilder", "I have", left, "left")
+    SU.debug("pagebuilder", "totalHeight", totalHeight, "with target", target)
+    local badness = 0
+    if _left < 0 then badness = 1000000 end
+    if node.is_penalty then
+      if node.penalty < -3000 then badness = 100000
+      else badness = -_left * _left - node.penalty
+      end
+    end
+    if badness > 0 then
+      local onepage = {}
+      for j = 1, bestBreak do
+        onepage[j] = table.remove(vboxlist, 1)
+      end
+      while #onepage > 1 and onepage[#onepage].discardable do
+        onepage[#onepage] = nil
+      end
+      return onepage, 1000
+    end
+    bestBreak = i
+  end
+  return false, false
+end
+
+return pagebuilder