Refactor scrollbar into its own file (#1124)

* Move scrollbar to its own file * Don't call `Scrollbar` functions if `View` is not scrollable * Allow horizontal scrolling in `Scrollbar` * Add horizontal scrollbar to `View` * Add `root:horizontal-scroll` command with `shift+wheel` keymap * Prioritize vertical scrollbar hover * Don't send mouse movement to vertical scrollbar when dragging horizontal one * Fix clicking on horizontal scrollbar track * Implement `start` scrollbar alignment * Add documentation to `Scrollbar` * Make `DocView` infinitely scrollable horizontally * Handle horizontal scroll SDL event
2022-10-15 20:12:15 -04:00
parent 5c2c95765e
commit 6b754eb628
11 changed files with 442 additions and 134 deletions
@@ -1,8 +1,8 @@
 local core = require "core"
 local config = require "core.config"
-local style = require "core.style"
 local common = require "core.common"
 local Object = require "core.object"
+local Scrollbar = require "core.scrollbar"

 ---@class core.view.position
 ---@field x number
@@ -28,10 +28,6 @@ local Object = require "core.object"
 ---@field w core.view.thumbtrackwidth
 ---@field h core.view.thumbtrack

---@class core.view.increment
---@field value number
---@field to number
-
 ---@alias core.view.cursor "'arrow'" | "'ibeam'" | "'sizeh'" | "'sizev'" | "'hand'"

 ---@alias core.view.mousebutton "'left'" | "'right'"
@@ -47,8 +43,8 @@ local Object = require "core.object"
 ---@field scroll core.view.scroll
 ---@field cursor core.view.cursor
 ---@field scrollable boolean
---@field scrollbar core.view.scrollbar
---@field scrollbar_alpha core.view.increment
+---@field v_scrollbar core.scrollbar
+---@field h_scrollbar core.scrollbar
 ---@field current_scale number
 local View = Object:extend()

@@ -63,13 +59,8 @@ function View:new()
  self.scroll = { x = 0, y = 0, to = { x = 0, y = 0 } }
  self.cursor = "arrow"
  self.scrollable = false
-  self.scrollbar = {
-    x = { thumb = 0, track = 0 },
-    y = { thumb = 0, track = 0 },
-    w = { thumb = 0, track = 0, to = { thumb = 0, track = 0 } },
-    h = { thumb = 0, track = 0 },
-  }
-  self.scrollbar_alpha = { value = 0, to = 0 }
+  self.v_scrollbar = Scrollbar("v", "e")
+  self.h_scrollbar = Scrollbar("h", "e")
  self.current_scale = SCALE
 end

@@ -111,47 +102,9 @@ function View:get_scrollable_size()
  return math.huge
 end

-
---@return number x
---@return number y
---@return number width
---@return number height
-function View:get_scrollbar_track_rect()
-  local sz = self:get_scrollable_size()
-  if sz <= self.size.y or sz == math.huge then
-    return 0, 0, 0, 0
-  end
-  local width = style.scrollbar_size
-  if self.hovered_scrollbar_track or self.dragging_scrollbar then
-    width = style.expanded_scrollbar_size
-  end
-  return
-    self.position.x + self.size.x - width,
-    self.position.y,
-    width,
-    self.size.y
-end
-
-
---@return number x
---@return number y
---@return number width
---@return number height
-function View:get_scrollbar_rect()
-  local sz = self:get_scrollable_size()
-  if sz <= self.size.y or sz == math.huge then
-    return 0, 0, 0, 0
-  end
-  local h = math.max(20, self.size.y * self.size.y / sz)
-  local width = style.scrollbar_size
-  if self.hovered_scrollbar_track or self.dragging_scrollbar then
-    width = style.expanded_scrollbar_size
-  end
-  return
-    self.position.x + self.size.x - width,
-    self.position.y + self.scroll.y * (self.size.y - h) / (sz - self.size.y),
-    width,
-    h
+---@return number
+function View:get_h_scrollable_size()
+  return 0
 end


@@ -159,16 +112,19 @@ end
 ---@param y number
 ---@return boolean
 function View:scrollbar_overlaps_point(x, y)
-  local sx, sy, sw, sh = self:get_scrollbar_rect()
-  return x >= sx - style.scrollbar_size * 3 and x < sx + sw and y > sy and y <= sy + sh
+  return not (not (self.v_scrollbar:overlaps(x, y) or self.h_scrollbar:overlaps(x, y)))
 end

---@param x number
---@param y number
+
 ---@return boolean
-function View:scrollbar_track_overlaps_point(x, y)
-  local sx, sy, sw, sh = self:get_scrollbar_track_rect()
-  return x >= sx - style.scrollbar_size * 3 and x < sx + sw and y > sy and y <= sy + sh
+function View:scrollbar_dragging()
+  return self.v_scrollbar.dragging or self.h_scrollbar.dragging
+end
+
+
+---@return boolean
+function View:scrollbar_hovering()
+  return self.v_scrollbar.hovering.track or self.h_scrollbar.hovering.track
 end


@@ -178,14 +134,18 @@ end
 ---@param clicks integer
 ---return boolean
 function View:on_mouse_pressed(button, x, y, clicks)
-  if self:scrollbar_track_overlaps_point(x, y) then
-    if self:scrollbar_overlaps_point(x, y) then
-      self.dragging_scrollbar = true
-    else
-      local _, _, _, sh = self:get_scrollbar_rect()
-      local ly = (y - self.position.y) - sh / 2
-      local pct = common.clamp(ly / self.size.y, 0, 100)
-      self.scroll.to.y = self:get_scrollable_size() * pct
+  if not self.scrollable then return end
+  local result = self.v_scrollbar:on_mouse_pressed(button, x, y, clicks)
+  if result then
+    if result ~= true then
+      self.scroll.to.y = result * self:get_scrollable_size()
+    end
+    return true
+  end
+  result = self.h_scrollbar:on_mouse_pressed(button, x, y, clicks)
+  if result then
+    if result ~= true then
+      self.scroll.to.x = result * self:get_h_scrollable_size()
    end
    return true
  end
@@ -196,7 +156,9 @@ end
 ---@param x number
 ---@param y number
 function View:on_mouse_released(button, x, y)
-  self.dragging_scrollbar = false
+  if not self.scrollable then return end
+  self.v_scrollbar:on_mouse_released(button, x, y)
+  self.h_scrollbar:on_mouse_released(button, x, y)
 end


@@ -205,22 +167,41 @@ end
 ---@param dx number
 ---@param dy number
 function View:on_mouse_moved(x, y, dx, dy)
-  if self.dragging_scrollbar then
-    local delta = self:get_scrollable_size() / self.size.y * dy
-    self.scroll.to.y = self.scroll.to.y + delta
-    if not config.animate_drag_scroll then
-      self:clamp_scroll_position()
-      self.scroll.y = self.scroll.to.y
+  if not self.scrollable then return end
+  local result
+  if self.h_scrollbar.dragging then goto skip_v_scrollbar end
+  result = self.v_scrollbar:on_mouse_moved(x, y, dx, dy)
+  if result then
+    if result ~= true then
+      self.scroll.to.y = result * self:get_scrollable_size()
+      if not config.animate_drag_scroll then
+        self:clamp_scroll_position()
+        self.scroll.y = self.scroll.to.y
+      end
    end
+    -- hide horizontal scrollbar
+    self.h_scrollbar:on_mouse_left()
+    return true
+  end
+  ::skip_v_scrollbar::
+  result = self.h_scrollbar:on_mouse_moved(x, y, dx, dy)
+  if result then
+    if result ~= true then
+      self.scroll.to.x = result * self:get_h_scrollable_size()
+      if not config.animate_drag_scroll then
+        self:clamp_scroll_position()
+        self.scroll.x = self.scroll.to.x
+      end
+    end
+    return true
  end
-  self.hovered_scrollbar = self:scrollbar_overlaps_point(x, y)
-  self.hovered_scrollbar_track = self.hovered_scrollbar or self:scrollbar_track_overlaps_point(x, y)
 end


 function View:on_mouse_left()
-  self.hovered_scrollbar = false
-  self.hovered_scrollbar_track = false
+  if not self.scrollable then return end
+  self.v_scrollbar:on_mouse_left()
+  self.h_scrollbar:on_mouse_left()
 end


@@ -238,14 +219,17 @@ function View:on_text_input(text)
  -- no-op
 end

+
 function View:on_ime_text_editing(text, start, length)
  -- no-op
 end

---@param y number
---@return boolean
-function View:on_mouse_wheel(y)

+---@param y number @Vertical scroll delta; positive is "up"
+---@param x number @Horizontal scroll delta; positive is "left"
+---@return boolean @Capture event
+function View:on_mouse_wheel(y, x)
+  -- no-op
 end

 ---Can be overriden to listen for scale change events to apply
@@ -273,27 +257,22 @@ end
 function View:clamp_scroll_position()
  local max = self:get_scrollable_size() - self.size.y
  self.scroll.to.y = common.clamp(self.scroll.to.y, 0, max)
+
+  max = self:get_h_scrollable_size() - self.size.x
+  self.scroll.to.x = common.clamp(self.scroll.to.x, 0, max)
 end


 function View:update_scrollbar()
-    local x, y, w, h = self:get_scrollbar_rect()
-    self.scrollbar.w.to.thumb = w
-    self:move_towards(self.scrollbar.w, "thumb", self.scrollbar.w.to.thumb, 0.3, "scroll")
-    self.scrollbar.x.thumb = x + w - self.scrollbar.w.thumb
-    self.scrollbar.y.thumb = y
-    self.scrollbar.h.thumb = h
+  local v_scrollable = self:get_scrollable_size()
+  self.v_scrollbar:set_size(self.position.x, self.position.y, self.size.x, self.size.y, v_scrollable)
+  self.v_scrollbar:set_percent(self.scroll.y/v_scrollable)
+  self.v_scrollbar:update()

-    local x, y, w, h = self:get_scrollbar_track_rect()
-    self.scrollbar.w.to.track = w
-    self:move_towards(self.scrollbar.w, "track", self.scrollbar.w.to.track, 0.3, "scroll")
-    self.scrollbar.x.track = x + w - self.scrollbar.w.track
-    self.scrollbar.y.track = y
-    self.scrollbar.h.track = h
-
-    -- we use 100 for a smoother transition
-    self.scrollbar_alpha.to = (self.hovered_scrollbar_track or self.dragging_scrollbar) and 100 or 0
-    self:move_towards(self.scrollbar_alpha, "value", self.scrollbar_alpha.to, 0.3, "scroll")
+  local h_scrollable = self:get_h_scrollable_size()
+  self.h_scrollbar:set_size(self.position.x, self.position.y, self.size.x, self.size.y, h_scrollable)
+  self.h_scrollbar:set_percent(self.scroll.x/h_scrollable)
+  self.h_scrollbar:update()
 end


@@ -306,7 +285,7 @@ function View:update()
  self:clamp_scroll_position()
  self:move_towards(self.scroll, "x", self.scroll.to.x, 0.3, "scroll")
  self:move_towards(self.scroll, "y", self.scroll.to.y, 0.3, "scroll")
-
+  if not self.scrollable then return end
  self:update_scrollbar()
 end

@@ -319,29 +298,11 @@ function View:draw_background(color)
 end


-function View:draw_scrollbar_track()
-  if not (self.hovered_scrollbar_track or self.dragging_scrollbar)
-     and self.scrollbar_alpha.value == 0 then
-    return
-  end
-  local color = { table.unpack(style.scrollbar_track) }
-  color[4] = color[4] * self.scrollbar_alpha.value / 100
-  renderer.draw_rect(self.scrollbar.x.track, self.scrollbar.y.track,
-                     self.scrollbar.w.track, self.scrollbar.h.track, color)
-end
-
-
-function View:draw_scrollbar_thumb()
-  local highlight = self.hovered_scrollbar or self.dragging_scrollbar
-  local color = highlight and style.scrollbar2 or style.scrollbar
-  renderer.draw_rect(self.scrollbar.x.thumb, self.scrollbar.y.thumb,
-                     self.scrollbar.w.thumb, self.scrollbar.h.thumb, color)
-end
-
-
 function View:draw_scrollbar()
-  self:draw_scrollbar_track()
-  self:draw_scrollbar_thumb()
+  self.v_scrollbar:draw_track()
+  self.v_scrollbar:draw_thumb()
+  self.h_scrollbar:draw_track()
+  self.h_scrollbar:draw_thumb()
 end