support for key-val extended image directives (only “width” for now).

2 files changed, 61 insertions, 9 deletions

diff --git a/rst_context.lua b/rst_context.lua
index e64aac4..f17f5a6 100644
--- a/rst_context.lua
+++ b/rst_context.lua
@@ -1085,8 +1085,6 @@ function rst_context.directive(directive, ...)
     local rd = rst_context.directives
     rst_context.addsetups("directive")
     local data = {...}
-    --print(directive, data, #data)
-    --for i,j in next,data do print(i,j) end
     local result = ""
     if rd[directive] then
         result = rd[directive](data)
@@ -1178,9 +1176,43 @@ end
 
 rst_context.directives = {}
 rst_context.directives.anonymous = 0
-rst_context.directives.images_done = {}
+rst_context.directives.images        = {}
+rst_context.directives.images.done   = {}
+rst_context.directives.images.values = {}
+
+rst_context.directives.images.keys = {
+    ["width"]   = "width",
+    ["size"]    = "width",
+    ["caption"] = "caption",
+}
+
+rst_context.directives.images.values.width = {
+    ["fit"]    = "\\hsize",
+    ["hsize"]  = "\\hsize",
+    ["broad"]  = "\\hsize",
+    ["normal"] = "local",
+    ["normal"] = "local",
+}
 
+-- we won't allow passing arbitrary setups to context
+rst_context.directives.images.permitted_setups = {
+    "width"
+}
+
+local function img_setup (properties)
+    local result = ""
+    for _, prop in next, rst_context.directives.images.permitted_setups do
+        if properties[prop] then
+            result = result .. prop .. "=" .. properties[prop] .. ","
+        end
+    end
+    if result ~= "" then
+        result = "[" .. result .. "]"
+    end
+    return result
+end
 rst_context.directives.image = function(name, data)
+    local properties = {}
     local anon = false
     local rd = rst_context.directives
     if not data then -- this makes the “name” argument optional
@@ -1189,17 +1221,30 @@ rst_context.directives.image = function(name, data)
         anon = true -- indicates a nameless picture
         name = "anonymous" .. rd.anonymous
     end
+    properties.caption = name
+    properties.width = "\\local"
 
     local processed = "" -- stub; TODO do something useful with optional dimension specifications
     if type(data) == "table" then -- should always be true
+        local p = helpers.patterns
         for _, str in ipairs(data) do
-            processed = processed .. (str and str ~= "" and string.strip(str))
+            local key, val
+            key, val = p.colon_keyval:match(str)
+            local rdi = rst_context.directives.images
+            if key and val then
+                key = rdi.keys[key] -- sanitize key expression
+                val = rdi.values[key] and rdi.values[key][val] or val -- e.g. captions have no substitutions
+                properties[key] = val
+            else
+                processed = processed .. (str and str ~= "" and string.strip(str))
+            end
         end
     end
+    properties.setup = img_setup(properties) or ""
     data = processed
     processed = nil
     local img = ""
-    local images_done = rd.images_done
+    local images_done = rd.images.done
     if not anon then
         if not images_done[name] then
             img = img .. string.format([[
@@ -1210,14 +1255,14 @@ rst_context.directives.image = function(name, data)
         end
         img = img .. string.format([[
 \def\RSTsubstitution%s{%
-  \placefigure[here]{%s}{\externalfigure[%s]}
+  \placefigure[here]{%s}{\externalfigure[%s]%s}
 }
-]], name, name, name)
+]], name, properties.caption, name, properties.setup)
     else -- image won't be referenced but used instantly
         img = img .. string.format([[
 
-\placefigure[here]{none}{\externalfigure[%s]}
-]], data)
+\placefigure[here]{%s}{\externalfigure[%s]%s}
+]], properties.caption, data, properties.setup)
     end
     return img
 end
diff --git a/rst_helpers.lua b/rst_helpers.lua
index b8902ca..33c1a80 100644
--- a/rst_helpers.lua
+++ b/rst_helpers.lua
@@ -90,6 +90,13 @@ do
 
     p.whitespace = S" \t\v\r\n"^1
     p.strip = p.whitespace^0 * C((1 - (p.whitespace * p.last))^1) * p.whitespace^0 * p.last
+
+
+    local colon = P":"
+    local escaped_colon = P"\\:"
+    local nocolon = (escaped_colon + (1 - colon))^1
+    p.colon_right = nocolon * colon
+    p.colon_keyval = C(nocolon) * colon * p.space^1 * C((1 - (p.space^0 * P(-1)))^1)
 end
 
 function helpers.cell.create(raw, n_row, n_col, parent, variant)