Managed layout of entities and XML tags (Used by Gosu) in TextArea te…

…xt better (tags still don't like newlines inside them). Added editable attribute to TextArea (Allows selection, but not alteration). Added TextArea#stripped_text to get the underlying text, stripped of tags and attributes.

examples/text_area_example.rb

@@ -4,22 +4,27 @@ class ExampleState < Fidgit::GuiState
   def initialize
     super
 
+    Gosu.register_entity(:entity, Gosu::Image["head_icon.png"])
+
+    string = "<c=3333ff>Hello, my name</c> is <c=ff0000>Brian</c> the&entity;&entity;snail<c=00ff00>!\nHi\nHello!</c>"
     horizontal do
       vertical do
-        label 'editable'
-        text_area(width: 200)
+        label 'disabled'
+        text_area(text: "Can't even select this text", width: 200, enabled: false)
       end
 
       vertical do
         label 'mirrors to right'
-        text_area(width: 200, text: "Hello, my name in brian the snail!") do |sender, text|
+        text_area(width: 200, text: string) do |_, text|
           @mirror.text = text
         end
       end
 
       vertical do
-        label 'not editable'
-        @mirror = text_area(width: 200, enabled: false)
+        my_label = label 'not editable'
+        font = Gosu::Font.new($window, "", my_label.font.height)
+        font["a"] = Gosu::Image["head_icon.png"]
+        @mirror = text_area(text: string, width: 200, editable: false, font: font)
       end
     end
   end

lib/fidgit/elements/text_area.rb

@@ -2,6 +2,8 @@
 
 module Fidgit
   class TextArea < Element
+    ENTITY_PLACEHOLDER = "*"
+
     # @return [Number]
     attr_reader :min_height
     # @return [Number]
@@ -14,13 +16,16 @@ class TextArea < Element
     # @return [Boolean]
     attr_writer :editable
 
+    # @return [String] Text, but stripped of tags.
+    attr_reader :stripped_text
+
     event :changed
     event :focus
     event :blur
 
-    # Is the area editable?
+    # Is the area editable? This will always be false if the Element is disabled.
     def editable?
-      enabled?
+      enabled? and @editable
     end
 
     # Text within the element.
@@ -43,7 +48,7 @@ def selection_range
     #
     # @return [String]
     def selection_text
-      text[selection_range]
+      stripped_text[selection_range]
     end
 
     # Sets the text within the selection. The caret will be placed at the end of the inserted text.
@@ -52,10 +57,14 @@ def selection_text
     # @return [String] The new selection text.
     def selection_text=(str)
       from = [@text_input.selection_start, @text_input.caret_pos].min
+      to = [@text_input.selection_start, @text_input.caret_pos].max
       new_length = str.length
 
       full_text = text
-      full_text[selection_range] = str.encode('UTF-8', undef: :replace)
+      tags_length_before = (0...from).inject(0) {|m, i| m + @tags[i].length }
+      tags_length_inside = (from...to).inject(0) {|m, i| m + @tags[i].length }
+      range = (selection_range.first + tags_length_before)...(selection_range.last + tags_length_before + tags_length_inside)
+      full_text[range] = str.encode('UTF-8', undef: :replace)
       @text_input.text = full_text
 
       @text_input.selection_start = @text_input.caret_pos = from + new_length
@@ -79,7 +88,7 @@ def caret_position
     # @param [Integer] pos Position of caret in the text.
     # @return [Integer] New position of caret.
     def caret_position=(position)
-      raise ArgumentError, "Caret position must be in the range 0 to the length of the text (inclusive)" unless position.between?(0, text.length)
+      raise ArgumentError, "Caret position must be in the range 0 to the length of the text (inclusive)" unless position.between?(0, stripped_text.length)
       @text_input.caret_pos = position
 
       position
@@ -105,6 +114,7 @@ def text=(text)
     # @option options [Integer] :min_height
     # @option options [Integer] :max_height (Infinite)
     # @option options [Number] :line_spacing (0)
+    # @option options [Boolean] :editable (true)
     def initialize(options = {}, &block)
       options = {
         text: '',
@@ -116,13 +126,15 @@ def initialize(options = {}, &block)
         caret_period: default(:caret_period),
         focused_border_color: default(:focused, :border_color),
         selection_color: default(:selection_color),
+        editable: true,
       }.merge! options
 
       @line_spacing = options[:line_spacing]
       @caret_color = options[:caret_color].dup
       @caret_period = options[:caret_period]
       @focused_border_color = options[:focused_border_color].dup
       @selection_color = options[:selection_color].dup
+      @editable = options[:editable]
 
       @lines = [''] # List of lines of wrapped text.
       @caret_positions = [[0, 0]] # [x, y] of each position the caret can be in.
@@ -131,8 +143,10 @@ def initialize(options = {}, &block)
       @old_text = ''
       @old_caret_position = 0
       @old_selection_start = 0
+      @tags = Hash.new("") # Hash of tags embedded in the text.
 
       @text_input.text = options[:text].dup
+      @stripped_text = '' # Text stripped of xml tags.
 
       super(options)
 
@@ -195,14 +209,20 @@ def blur(sender)
     # @return [nil]
     def draw_foreground
       # Always roll back changes made by the user unless the text is editable.
-      if not editable? and text != @old_text
-        @text_input.text = @old_text
-        @text_input.selection_start = @old_selection_start
-        self.caret_position = @old_caret_position
-      else
+      if editable? or text == @old_text
         recalc if focused? # Workaround for Windows draw/update bug.
         @old_caret_position = caret_position
         @old_selection_start = @text_input.selection_start
+      else
+        roll_back
+      end
+
+      if caret_position > stripped_text.length
+        self.caret_position = stripped_text.length
+      end
+
+      if @text_input.selection_start >= stripped_text.length
+        @text_input.selection_start = stripped_text.length
       end
 
       # Draw the selection.
@@ -236,7 +256,8 @@ def y_at_line(lines_number)
     # Helper for #recalc
     # @return [Integer]
     def position_letters_in_word(word, line_width)
-      word.each_char do |c|
+      # Strip tags before measuring word.
+      word.gsub(/<[^>]*>|&[^;];/, '').each_char do |c|
         char_width = font.text_width(c)
         line_width += char_width
         @caret_positions.push [line_width, y_at_line(@lines.size)]
@@ -271,8 +292,23 @@ def layout
       word = ''
       word_width = 0
 
-      text.each_char do |char|
-        char_width = (char == "\n") ? 0 : font.text_width(char)
+      strip_tags
+
+      stripped_text.each_char.with_index do |char, i|
+        tag = @tags[i]
+
+        # \x0 is just a place-holder for an entity: &entity;
+        if char == ENTITY_PLACEHOLDER
+          char = tag
+          tag = ""
+        end
+
+        case char
+          when "\n"
+            char_width = 0
+          else
+            char_width = font.text_width char
+        end
 
         overall_width = line_width + (line_width == 0 ? 0 : space_width) + word_width + char_width
         if overall_width > max_width and not (char == ' ' and not word.empty?)
@@ -282,7 +318,7 @@ def layout
             position_letters_in_word(word, line_width)
 
             # Push as much of the current word as possible as a complete line.
-            @lines.push word + (char == ' ' ? '' : '-')
+            @lines.push word + tag + (char == ' ' ? '' : '-')
             line_width = font.text_width(word)
 
             word = ''
@@ -294,18 +330,18 @@ def layout
             line = ''
           end
 
-          @char_widths[-1] += (width - line_width - padding_left - padding_right) unless @char_widths.empty?
+          widen_last_character line_width
           line_width = 0
         end
 
         case char
           when "\n"
             # A new-line ends the word and puts it on the line.
-            line += word
+            line += word + tag
             line_width = position_letters_in_word(word, line_width)
             @caret_positions.push [line_width, y_at_line(@lines.size)]
-            @char_widths[-1] += (width - line_width - (padding_left + padding_right)) unless @char_widths.empty?
             @char_widths.push 0
+            widen_last_character line_width
             @lines.push line
             word = ''
             word_width = 0
@@ -314,7 +350,7 @@ def layout
 
           when ' '
             # A space ends a word and puts it on the line.
-            line += word + char
+            line += word + tag + char
             line_width = position_letters_in_word(word, line_width)
             line_width += space_width
             @caret_positions.push [line_width, y_at_line(@lines.size)]
@@ -330,14 +366,15 @@ def layout
             end
 
             # Start building up a new word.
-            word += char
+            word += tag + char
             word_width += char_width
         end
       end
 
       # Add any remaining word on the last line.
       unless word.empty?
-        position_letters_in_word(word, line_width)
+        line_width = position_letters_in_word(word, line_width)
+        @char_widths << width - line_width - padding_left - padding_right
         line += word
       end
 
@@ -351,35 +388,40 @@ def layout
         @old_caret_position = caret_position
         @old_selection_start = @text_input.selection_start
       else
-        # Roll back!
-        @lines = old_lines
-        @caret_positions = old_caret_positions
-        @char_widths = old_char_widths
-        @text_input.text = @old_text
-        self.caret_position = @old_caret_position
-        @text_input.selection_start = @old_selection_start
+        roll_back
       end
 
       nil
     end
 
+    protected
+    def roll_back
+      @text_input.text = @old_text
+      self.caret_position = @old_caret_position
+      @text_input.selection_start = @old_selection_start
+      recalc
+    end
+
+    protected
+    def widen_last_character(line_width)
+      @char_widths[-1] += (width - line_width - padding_left - padding_right) unless @char_widths.empty?
+    end
+
     public
     # Cut the selection and copy it to the clipboard.
     def cut
       str = selection_text
-      unless selection_text.empty?
+      unless str.empty?
         Clipboard.copy str
-        self.selection_text = ''
+        self.selection_text = '' if editable?
       end
     end
 
     public
     # Copy the selection to the clipboard.
     def copy
       str = selection_text
-      unless selection_text.empty?
-        Clipboard.copy str
-      end
+      Clipboard.copy str unless str.empty?
     end
 
     public
@@ -393,5 +435,28 @@ def paste
     def post_init_block(&block)
       subscribe :changed, &block
     end
+
+    protected
+    # Strip XML tags and entities ("<c=000000></c>" and "&entity;")
+    # @note Entities will mess up the system because we don't know how wide they are.
+    def strip_tags
+      tags_length = 0
+      @tags = Hash.new('')
+
+      @stripped_text = text.gsub(%r[(<[^>]*?>|&[^;]+;)]) do |tag|
+        pos = $`.length - tags_length
+        tags_length += tag.length
+        @tags[pos] += tag
+
+        # Entities need to have a non-printing character that can represent them.
+        # Still not right, but does mean there are the right number of characters.
+        if tag[0] == '&'
+          tags_length -= 1
+          ENTITY_PLACEHOLDER # Will be expanded later.
+        else
+          '' # Tags don't use up space, so ignore them.
+        end
+      end
+    end
   end
 end