Text highlighting: extend to include punctuations

When selected text seems to be a "sentence segment"
(that is, when there are punctuations around start
AND end), extend the selection to include the relevant
punctuation.
Do this only when saving highlights and for translation
(but not when dict or wikipedia lookups, or search).

frontend/apps/reader/modules/readerhighlight.lua

@@ -89,7 +89,7 @@ function ReaderHighlight:init()
             return {
                 text = _("Highlight"),
                 callback = function()
-                    this:saveHighlight()
+                    this:saveHighlight(true)
                     this:onClose()
                 end,
                 enabled = this.hold_pos ~= nil,
@@ -1371,6 +1371,14 @@ function ReaderHighlight:viewSelectionHTML(debug_view, no_css_files_buttons)
 end
 
 function ReaderHighlight:translate(selected_text, page, index)
+    if self.ui.rolling then
+        -- Extend the selected text to include any punctuation at start or end,
+        -- which may give a better translation with the added context.
+        local extended_text = self.ui.document:extendXPointersToSentenceSegment(selected_text.pos0, selected_text.pos1)
+        if extended_text then
+            selected_text = extended_text
+        end
+    end
     if selected_text.text ~= "" then
         self:onTranslateText(selected_text.text, page, index)
     -- or we will do OCR
@@ -1418,7 +1426,7 @@ function ReaderHighlight:onHoldRelease()
                 self.select_mode = false
                 self:extendSelection()
                 if default_highlight_action == "select" then
-                    self:saveHighlight()
+                    self:saveHighlight(true)
                     self:clear()
                 else
                     self:onShowHighlightMenu()
@@ -1452,7 +1460,7 @@ function ReaderHighlight:onHoldRelease()
                 -- bypass default action and show popup if long final hold
                 self:onShowHighlightMenu()
             elseif default_highlight_action == "highlight" then
-                self:saveHighlight()
+                self:saveHighlight(true)
                 self:onClose()
             elseif default_highlight_action == "select" then
                 self:startSelection()
@@ -1616,10 +1624,16 @@ function ReaderHighlight:getHighlightBookmarkItem()
     end
 end
 
-function ReaderHighlight:saveHighlight()
+function ReaderHighlight:saveHighlight(extend_to_sentence)
     self.ui:handleEvent(Event:new("AddHighlight"))
     logger.dbg("save highlight")
     if self.hold_pos and self.selected_text and self.selected_text.pos0 and self.selected_text.pos1 then
+        if extend_to_sentence and self.ui.rolling then
+            local extended_text = self.ui.document:extendXPointersToSentenceSegment(self.selected_text.pos0, self.selected_text.pos1)
+            if extended_text then
+                self.selected_text = extended_text
+            end
+        end
         local page = self.hold_pos.page
         if not self.view.highlight.saved[page] then
             self.view.highlight.saved[page] = {}
@@ -1668,7 +1682,7 @@ If you wish your highlights to be saved in the document, just move it to a writa
 end
 
 function ReaderHighlight:addNote(text)
-    local page, index = self:saveHighlight()
+    local page, index = self:saveHighlight(true)
     if text then self:clear() end
     self:editHighlight(page, index, true, text)
     UIManager:close(self.edit_highlight_dialog)

frontend/document/credocument.lua

@@ -835,6 +835,10 @@ function CreDocument:getTextFromXPointers(pos0, pos1, draw_selection)
     return self._document:getTextFromXPointers(pos0, pos1, draw_selection, draw_segmented_selection)
 end
 
+function CreDocument:extendXPointersToSentenceSegment(pos0, pos1)
+    return self._document:extendXPointersToSentenceSegment(pos0, pos1)
+end
+
 function CreDocument:getHTMLFromXPointer(xp, flags, from_final_parent)
     if xp then
         return self._document:getHTMLFromXPointer(xp, flags, from_final_parent)