path: root/plugins/minimap.lua

-- mod-version:3
local core = require "core"
local command = require "core.command"
local common = require "core.common"
local config = require "core.config"
local style = require "core.style"
local DocView = require "core.docview"
local Object = require "core.object"

-- Sample configurations:
-- full width:
-- config.plugins.minimap.highlight_width = 100
-- config.plugins.minimap.gutter_width = 0
-- left side:
-- config.plugins.minimap.highlight_align = 'left'
-- config.plugins.minimap.highlight_width = 3
-- config.plugins.minimap.gutter_width = 4
-- right side:
-- config.plugins.minimap.highlight_align = 'right'
-- config.plugins.minimap.highlight_width = 5
-- config.plugins.minimap.gutter_width = 0

-- General plugin settings
config.plugins.minimap = common.merge({
  enabled = true,
  width = 100,
  instant_scroll = false,
  syntax_highlight = true,
  scale = 1,
  -- hide on small docs (can be true, false or min number of lines)
  avoid_small_docs = false,
  -- how many spaces one tab is equivalent to
  tab_width = 4,
  draw_background = true,
  -- you can override these colors
  selection_color = nil,
  caret_color = nil,
  -- If other plugins provide per-line highlights,
  -- this controls the placement. (e.g. gitdiff_highlight)
  highlight_align = 'left',
  highlight_width = 3,
  gutter_width = 5,
  -- The config specification used by the settings gui
  config_spec = {
    name = "Mini Map",
    {
      label = "Enabled",
      description = "Activate the minimap by default.",
      path = "enabled",
      type = "toggle",
      default = true
    },
    {
      label = "Width",
      description = "Width of the minimap in pixels.",
      path = "width",
      type = "number",
      default = 100,
      min = 50,
      max = 1000
    },
    {
      label = "Instant Scroll",
      description = "When enabled disables the scrolling animation.",
      path = "instant_scroll",
      type = "toggle",
      default = false
    },
    {
      label = "Syntax Highlighting",
      description = "Disable to improve performance.",
      path = "syntax_highlight",
      type = "toggle",
      default = true
    },
    {
      label = "Scale",
      description = "Size of the minimap using a scaling factor.",
      path = "scale",
      type = "number",
      default = 1,
      min = 0.5,
      max = 10,
      step = 0.1
    },
    {
      label = "Hide for small Docs",
      description = "Hide the minimap when a Doc is small enough.",
      path = "avoid_small_docs",
      type = "toggle",
      default = false
    },
    {
      label = "Small Docs definition",
      description = "Size of a Doc to be considered small. Use 0 to automatically decide.",
      path = "avoid_small_docs_len",
      type = "number",
      default = 0,
      min = 0,
      on_apply = function(value)
        if value == 0 then
          config.plugins.minimap.avoid_small_docs = true
        else
          config.plugins.minimap.avoid_small_docs = value
        end
      end
    },
    {
      label = "Tabs Width",
      description = "The amount of spaces that represent a tab.",
      path = "tab_width",
      type = "number",
      default = 4,
      min = 1,
      max = 8
    },
    {
      label = "Draw Background",
      description = "When disabled makes the minimap transparent.",
      path = "draw_background",
      type = "toggle",
      default = true
    },
    {
      label = "Selection Color",
      description = "Background color of selected text in html notation eg: #FFFFFF. Leave empty to use default.",
      path = "selection_color_html",
      type = "string",
      on_apply = function(value)
        if value and value:match("#%x%x%x%x%x%x") then
          config.plugins.minimap.selection_color = { common.color(value) }
        else
          config.plugins.minimap.selection_color = nil
        end
      end
    },
    {
      label = "Caret Color",
      description = "Background color of active line in html notation eg: #FFFFFF. Leave empty to use default.",
      path = "caret_color_html",
      type = "string",
      on_apply = function(value)
        if value and value:match("#%x%x%x%x%x%x") then
          config.plugins.minimap.caret_color = { common.color(value) }
        else
          config.plugins.minimap.caret_color = nil
        end
      end
    },
    {
      label = "Highlight Alignment",
      path = "highlight_align",
      type = "selection",
      default = "left",
      values = {
        {"Left", "left"},
        {"Right", "right"}
      }
    },
    {
      label = "Highlight Width",
      path = "highlight_width",
      type = "number",
      default = 3,
      min = 0,
      max = 50
    },
    {
      label = "Gutter Width",
      description = "Left padding of the minimap.",
      path = "gutter_width",
      type = "number",
      default = 5,
      min = 0,
      max = 50
    },
  }
}, config.plugins.minimap)

-- Configure size for rendering each char in the minimap
local char_height = 1 * SCALE * config.plugins.minimap.scale
local char_spacing = 0.8 * SCALE * config.plugins.minimap.scale
local line_spacing = 2 * SCALE * config.plugins.minimap.scale

local MiniMap = Object:extend()

function MiniMap:new()
end

function MiniMap:line_highlight_color(line_index)
  -- other plugins can override this, and return a color
end

local minimap = MiniMap()
local per_docview = setmetatable({}, { __mode = "k" })

local function show_minimap(docview)
  if not docview:is(DocView) then return false end
  if
    not config.plugins.minimap.enabled
    or not docview:is(DocView)
    or per_docview[docview] == false
  then
    return false
  end
  if config.plugins.minimap.avoid_small_docs then
    local last_line = #docview.doc.lines
    if type(config.plugins.minimap.avoid_small_docs) == "number" then
      return last_line > config.plugins.minimap.avoid_small_docs
    else
      local _, y = docview:get_line_screen_position(last_line, docview.doc.lines[last_line])
      y = y + docview.scroll.y - docview.position.y + docview:get_line_height()
      return y > docview.size.y
    end
  end
  return true
end

-- Overloaded since the default implementation adds a extra x3 size of hotspot for the mouse to hit the scrollbar.
local prev_scrollbar_overlaps_point = DocView.scrollbar_overlaps_point
DocView.scrollbar_overlaps_point = function(self, x, y)
  if not show_minimap(self) then
    return prev_scrollbar_overlaps_point(self, x, y)
  end

  local sx, sy, sw, sh = self:get_scrollbar_rect()
  return x >= sx and x < sx + sw and y >= sy and y < sy + sh
end

-- Helper function to determine if current file is too large to be shown fully inside the minimap area.
local function is_file_too_large(self)
  local line_count = #self.doc.lines
  local _, _, _, sh = self:get_scrollbar_rect()

  -- check if line count is too large to fit inside the minimap area
  local max_minmap_lines = math.floor(sh / line_spacing)
  return line_count > 1 and line_count > max_minmap_lines
end

-- Overloaded with an extra check if the user clicked inside the minimap to automatically scroll to that line.
local prev_on_mouse_pressed = DocView.on_mouse_pressed
DocView.on_mouse_pressed = function(self, button, x, y, clicks)
  if not show_minimap(self) then
    return prev_on_mouse_pressed(self, button, x, y, clicks)
  end

  -- check if user clicked in the minimap area and jump directly to that line
  -- unless they are actually trying to perform a drag
  local minimap_hit = self:scrollbar_overlaps_point(x, y)
  if minimap_hit then
    local line_count = #self.doc.lines
    local minimap_height = line_count * line_spacing

    -- check if line count is too large to fit inside the minimap area
    local is_too_large = is_file_too_large(self)
    if is_too_large then
      local _, _, _, sh = self:get_scrollbar_rect()
      minimap_height = sh
    end

    -- calc which line to jump to
    local dy = y - self.position.y
    local jump_to_line = math.floor((dy / minimap_height) * line_count) + 1

    local _, cy, _, cy2 = self:get_content_bounds()
    local lh = self:get_line_height()
    local visible_lines_count = math.max(1, (cy2 - cy) / lh)
    local visible_lines_start = math.max(1, math.floor(cy / lh))

    -- calc if user hit the currently visible area
    local hit_visible_area = true
    if is_too_large then

      local visible_height = visible_lines_count * line_spacing
      local scroll_pos = (visible_lines_start - 1) /
                                 (line_count - visible_lines_count - 1)
      scroll_pos = math.min(1.0, scroll_pos) -- 0..1
      local visible_y = self.position.y + scroll_pos *
                                (minimap_height - visible_height)

      local t = (line_count - visible_lines_start) / visible_lines_count
      if t <= 1 then visible_y = visible_y + visible_height * (1.0 - t) end

      if y < visible_y or y > visible_y + visible_height then
        hit_visible_area = false
      end
    else

      -- If the click is on the currently visible line numbers,
      -- ignore it since then they probably want to initiate a drag instead.
      if jump_to_line < visible_lines_start or jump_to_line > visible_lines_start +
              visible_lines_count then hit_visible_area = false end
    end

    -- if user didn't click on the visible area (ie not dragging), scroll accordingly
    if not hit_visible_area then
      self:scroll_to_line(jump_to_line, false, config.plugins.minimap.instant_scroll)
    end

  end

  return prev_on_mouse_pressed(self, button, x, y, clicks)
end

-- Overloaded with pretty much the same logic as original DocView implementation,
-- with the exception of the dragging scrollbar delta. We want it to behave a bit snappier
-- since the "scrollbar" essentially represents the lines visible in the content view.
local prev_on_mouse_moved = DocView.on_mouse_moved
DocView.on_mouse_moved = function(self, x, y, dx, dy)
  if not show_minimap(self) then
    return prev_on_mouse_moved(self, x, y, dx, dy)
  end

  if self.dragging_scrollbar then
    local line_count = #self.doc.lines
    local lh = self:get_line_height()
    local delta = lh / line_spacing * dy

    if is_file_too_large(self) then
      local _, sy, _, sh = self:get_scrollbar_rect()
      delta = (line_count * lh) / sh * dy
    end

    self.scroll.to.y = self.scroll.to.y + delta
  end

  -- we need to "hide" that the scrollbar is dragging so that View doesnt does its own scrolling logic
  local t = self.dragging_scrollbar
  self.dragging_scrollbar = false
  local r = prev_on_mouse_moved(self, x, y, dx, dy)
  self.dragging_scrollbar = t
  return r
end

-- Overloaded since we want the mouse to interact with the full size of the minimap area,
-- not juse the scrollbar.
local prev_get_scrollbar_rect = DocView.get_scrollbar_rect
DocView.get_scrollbar_rect = function(self)
  if not show_minimap(self) then return prev_get_scrollbar_rect(self) end

  return self.position.x + self.size.x - config.plugins.minimap.width * SCALE,
         self.position.y, config.plugins.minimap.width * SCALE, self.size.y
end

local prev_get_scrollbar_track_rect = DocView.get_scrollbar_track_rect
DocView.get_scrollbar_track_rect = function(self)
  if not show_minimap(self) then return prev_get_scrollbar_track_rect(self) end

  return self.position.x + self.size.x - config.plugins.minimap.width * SCALE,
         self.position.y, config.plugins.minimap.width * SCALE, self.size.y
end

-- Overloaded so we can render the minimap in the "scrollbar area".
local prev_draw_scrollbar = DocView.draw_scrollbar
DocView.draw_scrollbar = function(self)
  if not show_minimap(self) then return prev_draw_scrollbar(self) end

  local x, y, w, h = self:get_scrollbar_rect()

  local highlight = self.hovered_scrollbar or self.dragging_scrollbar
  local visual_color = highlight and style.scrollbar2 or style.scrollbar

  local _, cy, _, cy2 = self:get_content_bounds()
  local lh = self:get_line_height()
  local visible_lines_count = math.max(1, (cy2 - cy) / lh)
  local visible_lines_start = math.max(1, math.floor(cy / lh))
  local scroller_height = visible_lines_count * line_spacing
  local line_count = #self.doc.lines

  local visible_y = self.position.y + (visible_lines_start - 1) * line_spacing

  -- check if file is too large to fit inside the minimap area
  local max_minmap_lines = math.floor(h / line_spacing)
  local minimap_start_line = 1
  if is_file_too_large(self) then

    local scroll_pos = (visible_lines_start - 1) /
                               (line_count - visible_lines_count - 1)
    scroll_pos = math.min(1.0, scroll_pos) -- 0..1, procent of visual area scrolled

    local scroll_pos_pixels = scroll_pos * (h - scroller_height)
    visible_y = self.position.y + scroll_pos_pixels

    -- offset visible area if user is scrolling past end
    local t = (line_count - visible_lines_start) / visible_lines_count
    if t <= 1 then visible_y = visible_y + scroller_height * (1.0 - t) end

    minimap_start_line = visible_lines_start -
                                 math.floor(scroll_pos_pixels / line_spacing)
    minimap_start_line = math.max(1, math.min(minimap_start_line,
                                              line_count - max_minmap_lines))
  end

  if config.plugins.minimap.draw_background then
    renderer.draw_rect(x, y, w, h, style.minimap_background or style.background)
  end
  -- draw visual rect
  renderer.draw_rect(x, visible_y, w, scroller_height, visual_color)

  -- highlight the selected lines, and the line with the caret on it
  local selection_color = config.plugins.minimap.selection_color or style.dim
  local caret_color = config.plugins.minimap.caret_color or style.caret
  local selection_line, selection_col, selection_line2, selection_col2 = self.doc:get_selection()
  local selection_y = y + (selection_line - minimap_start_line) * line_spacing
  local selection2_y = y + (selection_line2 - minimap_start_line) * line_spacing
  local selection_min_y = math.min(selection_y, selection2_y)
  local selection_h = math.abs(selection2_y - selection_y)+1
  renderer.draw_rect(x, selection_min_y, w, selection_h, selection_color)
  renderer.draw_rect(x, selection_y, w, line_spacing, caret_color)

  local highlight_align = config.plugins.minimap.highlight_align
  local highlight_width = config.plugins.minimap.highlight_width
  local gutter_width = config.plugins.minimap.gutter_width

  -- time to draw the actual code, setup some local vars that are used in both highlighted and plain renderind.
  local line_y = y

  -- when not using syntax highlighted rendering, just use the normal color but dim it 50%.
  local color = style.syntax["normal"]
  color = {color[1], color[2], color[3], color[4] * 0.5}

  -- we try to "batch" characters so that they can be rendered as just one rectangle instead of one for each.
  local batch_width = 0
  local batch_start = x
  local minimap_cutoff_x = x + config.plugins.minimap.width * SCALE
  local batch_syntax_type = nil
  local function flush_batch(type)
    local old_color = color
    color = style.syntax[batch_syntax_type]
    if config.plugins.minimap.syntax_highlight and color ~= nil then
      -- fetch and dim colors
      color = {color[1], color[2], color[3], color[4] * 0.5}
    else
      color = old_color
    end
    if batch_width > 0 then
      renderer.draw_rect(batch_start, line_y, batch_width, char_height, color)
    end
    batch_syntax_type = type
    batch_start = batch_start + batch_width
    batch_width = 0
  end

  local highlight_x
  if highlight_align == 'left' then
    highlight_x = x
  else
    highlight_x = x + w - highlight_width
  end
  local function render_highlight(idx, line_y)
    local highlight_color = minimap:line_highlight_color(idx)
    if highlight_color then
      renderer.draw_rect(highlight_x, line_y, highlight_width, line_spacing, highlight_color)
    end
  end

  local endidx = minimap_start_line + max_minmap_lines
  endidx = math.min(endidx, line_count)
  -- render lines with syntax highlighting
  if config.plugins.minimap.syntax_highlight then

    -- keep track of the highlight type, since this needs to break batches as well
    batch_syntax_type = nil

    -- per line
    for idx = minimap_start_line, endidx do
      batch_syntax_type = nil
      batch_start = x + gutter_width
      batch_width = 0

      render_highlight(idx, line_y)

      -- per token
      for _, type, text in self.doc.highlighter:each_token(idx) do
        -- flush prev batch
        if not batch_syntax_type then batch_syntax_type = type end
        if batch_syntax_type ~= type then flush_batch(type) end

        -- per character
        for char in common.utf8_chars(text) do
          if char == " " or char == "\n" then
            flush_batch(type)
            batch_start = batch_start + char_spacing
          elseif char == "	" then
            flush_batch(type)
            batch_start = batch_start + (char_spacing * config.plugins.minimap.tab_width)
          elseif batch_start + batch_width > minimap_cutoff_x then
            flush_batch(type)
            break
          else
            batch_width = batch_width + char_spacing
          end

        end
      end
      flush_batch(nil)
      line_y = line_y + line_spacing
    end

  else -- render lines without syntax highlighting
    for idx = minimap_start_line, endidx do
      batch_start = x + gutter_width
      batch_width = 0

      render_highlight(idx, line_y)

      for char in common.utf8_chars(self.doc.lines[idx]) do
        if char == " " or char == "\n" then
          flush_batch()
          batch_start = batch_start + char_spacing
        elseif char == "	" then
          flush_batch()
          batch_start = batch_start + (char_spacing * config.plugins.minimap.tab_width)
        elseif batch_start + batch_width > minimap_cutoff_x then
          flush_batch()
        else
          batch_width = batch_width + char_spacing
        end
      end
      flush_batch()
      line_y = line_y + line_spacing
    end

  end

end

local prev_update = DocView.update
DocView.update = function (self)
  if not show_minimap(self) then return prev_update(self) end
  self.size.x = self.size.x - config.plugins.minimap.width * SCALE
  return prev_update(self)
end

command.add(nil, {
  ["minimap:toggle-visibility"] = function()
    config.plugins.minimap.enabled = not config.plugins.minimap.enabled
  end,
  ["minimap:toggle-syntax-highlighting"] = function()
    config.plugins.minimap.syntax_highlight = not config.plugins.minimap.syntax_highlight
  end
})

command.add("core.docview!", {
  ["minimap:toggle-visibility-for-current-view"] = function()
    per_docview[core.active_view] = per_docview[core.active_view] == false
  end
})

return minimap