Class: Tuile::Component::TextView

Inherits:
Tuile::Component show all
Defined in:
lib/tuile/component/text_view.rb

Overview

A read-only viewer for prose: chunks of formatted text that scroll vertically. Shape-wise a hybrid between Label (string-shaped content via #text=) and List (scroll keys, optional scrollbar, auto-scroll).

Text is modeled as a StyledString: embedded ‘n` are hard line breaks, lines wider than the viewport are word-wrapped via StyledString#wrap (style spans are preserved across wrap boundaries — unlike the older ANSI-as-bytes wrapping, color does not get dropped on continuation rows). #text= accepts a String (parsed via StyledString.parse, so embedded ANSI is honored) or a StyledString directly; #text always returns the StyledString. Use #append for incremental “log line” style updates; turn on #auto_scroll to keep the latest content in view.

TextView is meant to be the content of a Window — focus indication and keyboard-hint surfacing rely on the surrounding window chrome.

Instance Attribute Summary collapse

Attributes inherited from Tuile::Component

#key_shortcut, #parent, #rect

Instance Method Summary collapse

Methods inherited from Tuile::Component

#active=, #active?, #attached?, #children, #cursor_position, #depth, #find_shortcut_component, #focus, #keyboard_hint, #on_child_removed, #on_focus, #on_tree, #root, #screen

Constructor Details

#initialize ⇒ TextView

Returns a new instance of TextView.



22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
 
# File 'lib/tuile/component/text_view.rb', line 22

def initialize
  super
  # `@hard_lines` is the logical model — one entry per `\n`-delimited
  # line of the original text, width-independent. `@physical_lines` is
  # the rendered view — each hard line word-wrapped to `wrap_width`
  # and padded with trailing blanks, so painting a row is a lookup.
  # Resizing rebuilds `@physical_lines` from `@hard_lines`; `#append`
  # extends both.
  @hard_lines = []
  @physical_lines = []
  @text = StyledString::EMPTY
  @content_size = Size::ZERO
  @blank_line = StyledString::EMPTY
  @top_line = 0
  @auto_scroll = false
  @scrollbar_visibility = :gone
end

Instance Attribute Details

#auto_scroll ⇒ Boolean

Returns if true, mutating the text scrolls the viewport so the last line stays in view. Default ‘false`.

Returns:

  • (Boolean) —

    if true, mutating the text scrolls the viewport so the last line stays in view. Default ‘false`.



59
60
61
 
# File 'lib/tuile/component/text_view.rb', line 59

def auto_scroll
  @auto_scroll
end

#content_size ⇒ Size (readonly)

Returns longest hard-line’s display width × number of hard lines. Reported on the unwrapped text — wrap-aware sizing would be circular (width depends on width). Empty text returns ‘Size.new(0, 0)`. Maintained incrementally by #text= and #append, so reads are O(1).

Returns:

  • (Size) —

    longest hard-line’s display width × number of hard lines. Reported on the unwrapped text — wrap-aware sizing would be circular (width depends on width). Empty text returns ‘Size.new(0, 0)`. Maintained incrementally by #text= and #append, so reads are O(1).



158
159
160
 
# File 'lib/tuile/component/text_view.rb', line 158

def content_size
  @content_size
end

#scrollbar_visibility ⇒ Symbol

Returns ‘:gone` or `:visible`.

Returns:

  • (Symbol) —

    ‘:gone` or `:visible`.



55
56
57
 
# File 'lib/tuile/component/text_view.rb', line 55

def scrollbar_visibility
  @scrollbar_visibility
end

#top_line ⇒ Integer

Returns index of the first visible physical line.

Returns:

  • (Integer) —

    index of the first visible physical line.



52
53
54
 
# File 'lib/tuile/component/text_view.rb', line 52

def top_line
  @top_line
end

Instance Method Details

#append(str) ⇒ void

This method returns an undefined value.

Appends ‘str` as a new physical line. If the current text is empty, behaves like `text = str`; otherwise prepends a newline so the new content lands on a fresh line. Accepts the same input forms as #text=.

Cost is O(appended) rather than O(total) — the existing wrapped buffer is reused, only the new hard line(s) are wrapped and padded, and ‘@content_size` is updated incrementally. The cached #text is invalidated and rebuilt on demand.

Parameters:



90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
 
# File 'lib/tuile/component/text_view.rb', line 90

def append(str)
  screen.check_locked
  appended = StyledString.parse(str)
  if @hard_lines.empty?
    self.text = appended
    return
  end

  new_hard_lines = appended.lines
  @text = nil
  @hard_lines.concat(new_hard_lines)
  new_width = new_hard_lines.map(&:display_width).max || 0
  @content_size = Size.new(
    [@content_size.width, new_width].max,
    @content_size.height + new_hard_lines.size
  )
  width = wrap_width
  new_hard_lines.each { |hl| append_physical_lines(hl, width) }
  update_top_line_if_auto_scroll
  invalidate
end

#clear ⇒ void

This method returns an undefined value.

Clears the text. Equivalent to ‘text = “”`.



114
115
116
 
# File 'lib/tuile/component/text_view.rb', line 114

def clear
  self.text = StyledString::EMPTY
end

#focusable? ⇒ Boolean

Returns:

  • (Boolean) 


149
 
# File 'lib/tuile/component/text_view.rb', line 149

def focusable? = true

#handle_key(key) ⇒ Boolean

Parameters:

  • key (String)

Returns:

  • (Boolean) 


162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
 
# File 'lib/tuile/component/text_view.rb', line 162

def handle_key(key)
  return false unless active?
  return true if super

  case key
  when *Keys::DOWN_ARROWS then move_top_line_by(1)
  when *Keys::UP_ARROWS   then move_top_line_by(-1)
  when Keys::PAGE_DOWN    then move_top_line_by(viewport_lines)
  when Keys::PAGE_UP      then move_top_line_by(-viewport_lines)
  when Keys::CTRL_D       then move_top_line_by(viewport_lines / 2)
  when Keys::CTRL_U       then move_top_line_by(-viewport_lines / 2)
  when *Keys::HOMES, "g"  then move_top_line_to(0)
  when *Keys::ENDS_, "G"  then move_top_line_to(top_line_max)
  else return false
  end
  true
end

#handle_mouse(event) ⇒ void

This method returns an undefined value.

Parameters:



182
183
184
185
186
187
188
 
# File 'lib/tuile/component/text_view.rb', line 182

def handle_mouse(event)
  super
  case event.button
  when :scroll_down then move_top_line_by(4)
  when :scroll_up   then move_top_line_by(-4)
  end
end

#repaint ⇒ void

This method returns an undefined value.

Paints the text into Tuile::Component#rect.

Skips the Tuile::Component#repaint default’s auto-clear: every row is painted explicitly (with padded blanks past the last line), so the “fully draw over your rect” contract is met without an upfront wipe.



196
197
198
199
200
201
202
203
204
205
206
 
# File 'lib/tuile/component/text_view.rb', line 196

def repaint
  return if rect.empty?

  scrollbar = if scrollbar_visible?
                VerticalScrollBar.new(rect.height, line_count: @physical_lines.size, top_line: @top_line)
              end
  (0...rect.height).each do |row|
    line = paintable_line(row + @top_line, row, scrollbar)
    screen.print TTY::Cursor.move_to(rect.left, rect.top + row), line
  end
end

#tab_stop? ⇒ Boolean

Returns:

  • (Boolean) 


151
 
# File 'lib/tuile/component/text_view.rb', line 151

def tab_stop? = true

#text ⇒ StyledString

Returns the current text. Defaults to an empty StyledString. Internally the text is stored as an array of hard lines so #append can stay O(appended) instead of re-scanning the whole buffer; the joined StyledString returned here is reconstructed on first read after a mutation and cached, so repeated reads are O(1) but the first read after #append pays O(total spans).

Returns:

  • (StyledString) —

    the current text. Defaults to an empty StyledString. Internally the text is stored as an array of hard lines so #append can stay O(appended) instead of re-scanning the whole buffer; the joined StyledString returned here is reconstructed on first read after a mutation and cached, so repeated reads are O(1) but the first read after #append pays O(total spans).



47
48
49
 
# File 'lib/tuile/component/text_view.rb', line 47

def text
  @text ||= build_text
end

#text=(value) ⇒ void

This method returns an undefined value.

Replaces the text. Embedded ‘n` characters become hard line breaks. A `String` is parsed via StyledString.parse (so embedded ANSI is honored); a `StyledString` is used as-is; `nil` is coerced to an empty StyledString.

Parameters:



67
68
69
70
71
72
73
74
75
76
77
 
# File 'lib/tuile/component/text_view.rb', line 67

def text=(value)
  new_text = StyledString.parse(value)
  return if text == new_text

  @text = new_text
  @hard_lines = new_text.empty? ? [] : new_text.lines
  @content_size = compute_content_size
  rewrap
  update_top_line_if_auto_scroll
  invalidate
end