LouisGameDev · July 3, 2025 20:45 · Jul 3, 2025
diff --git a/frame_style_nil_bug_demo.lua b/frame_style_nil_bug_demo.lua
@@ -0,0 +1,242 @@
+--@module = true
+
+local gui = require('gui')
+local widgets = require('gui.widgets')
+
+local INVISIBLE_FRAME = {
+    frame_pen=gui.CLEAR_PEN,
+    signature_pen=false,
+}
+
+
+-- MAIN BUG TRIGGERED HERE
+-----------------------------------------
+BugDemoPanel = defclass(BugDemoPanel, widgets.Panel)
+BugDemoPanel.ATTRS {
+    --frame_style = INVISIBLE_FRAME 
+    -- ^ This is the key part that triggers the bug.
+    -- if style is nil, it will be nil and panel.lua::Panel_end_drag will never be called
+    -- https://github.com/DFHack/dfhack/blob/e3165854e80411eec584c74949c73000f2aa0dcb/library/lua/gui/widgets/containers/panel.lua#L497C1-L498C1
+    -- even if user intends to finish drag
+}
+-----------------------------------------
+
+function BugDemoPanel:onInput(keys)
+    local key_info = {}
+    for key, value in pairs(keys) do
+        table.insert(key_info, string.format("%s=%s", tostring(key), tostring(value)))
+    end
+
+    table.sort(key_info)
+
+    return BugDemoPanel.super.onInput(self, keys)
+end
+
+BugDemoWindow = defclass(BugDemoWindow, widgets.Window)
+BugDemoWindow.ATTRS {
+    view_id = 'bugdemo_window',
+    frame_title = 'Frame Style Bug Demo',
+    resizable = true,
+    resize_min = {w = 54, h = 20},
+    frame_inset = {l = 0, r = 0, t = 0, b = 0}
+}
+
+BugDemoScreen = defclass(BugDemoScreen, gui.ZScreen)
+BugDemoScreen.ATTRS {
+    view_id = 'bugdemo_screen',
+    focus_path = 'bugdemo',
+    pass_movement_keys = true,
+    defocusable = true
+}
+
+function BugDemoWindow:init()
+    self.resizing_panels = false
+
+    self:addviews{
+        BugDemoPanel {
+            view_id = 'category_panel',
+            frame = {l = 0, w = 22, t = 0, b = 1},
+            frame_inset = {l = 1, t = 0, b = 1, r = 1},
+            resizable = true,
+            resize_anchors = {l = false, t = false, r = true, b = true},
+            resize_min = {w = 24},
+            on_resize_begin = self:callback('onPanelResizeBegin'),
+            on_resize_end = self:callback('onPanelResizeEnd'),
+            subviews = {
+                widgets.Label {
+                    frame = {t = 0, l = 0},
+                    text = 'category_panel',
+                    text_pen = COLOR_YELLOW
+                }
+            }
+        },
+
+        widgets.Divider {
+            view_id = 'divider1',
+            frame = {l = 30, t = 0, b = 2, w = 1},
+            interior_b = true,
+            frame_style_t = false
+        },
+
+        widgets.Panel {
+            view_id = 'item_panel',
+            frame = {t = 1, b = 3, l = 25, r = 0},
+            resize_min = {w = 30, h = 10},
+            frame_inset = {l = 1, r = 0},
+            subviews = {
+                widgets.Label {
+                    view_id = 'item_header',
+                    frame = {t = 0, l = 0, r = 0, h = 1},
+                    text = 'item_panel',
+                    text_pen = COLOR_YELLOW
+                }
+            }
+        },
+
+        widgets.HelpButton {
+            command = "gui/stockmonitor",
+            frame = {r = 0, t = 1}
+        }, 
+
+        widgets.Divider {
+            frame = {l = 0, r = 0, b = 2, h = 1},
+            frame_style_l = false,
+            frame_style_r = false,
+            interior_l = true
+        }, 
+
+        widgets.Panel {
+            frame = {l = 0, r = 0, b = 1, h = 1},
+            frame_inset = {l = 1, r = 1, t = 0, w = 100},
+            subviews = {
+                widgets.HotkeyLabel {
+                    frame = {l = 0},
+                    key = 'CUSTOM_CTRL_R',
+                    label = 'Button A',
+                    auto_width = true,
+                    on_activate = function()
+                        self:testResize()
+                    end
+                }, 
+                widgets.HotkeyLabel {
+                    frame = {l = 25},
+                    key = 'CUSTOM_CTRL_O',
+                    label = 'Button B',
+                    auto_width = true,
+                    on_activate = function()
+                    end
+                }
+            }
+        }
+    }
+end
+
+function BugDemoWindow:testResize()
+    local category_panel = self.subviews.category_panel
+    if category_panel then
+        category_panel.frame.w = (category_panel.frame.w == 22) and 32 or 22
+        self:ensurePanelsRelSize()
+        self:updateLayout()
+    end
+end
+
+function BugDemoWindow:onPanelResizeBegin() 
+    self.resizing_panels = true
+end
+
+function BugDemoWindow:onPanelResizeEnd()
+    self.resizing_panels = false
+    self:ensurePanelsRelSize()
+    self:updateLayout()
+end
+
+function BugDemoWindow:ensurePanelsRelSize()
+    local category_panel = self.subviews.category_panel
+    local item_panel = self.subviews.item_panel
+    local divider1 = self.subviews.divider1
+
+    if not category_panel or not item_panel or not divider1 then return end
+
+    local main_width = self.frame.w or 100
+    local min_item_width = 30 
+
+    category_panel.frame.w =
+        math.min(math.max(category_panel.frame.w, 24), 
+                 main_width - min_item_width)
+
+    local cat_width = category_panel.frame.w
+    item_panel.frame.l = category_panel.visible and cat_width or 1
+    divider1.frame.l = item_panel.frame.l - 1
+end
+
+function BugDemoWindow:onRenderBody(dc)
+    if self.resizing_panels then
+        self:ensurePanelsRelSize()
+        self:updateLayout()
+    end
+    return BugDemoWindow.super.onRenderBody(self, dc)
+end
+
+function BugDemoWindow:preUpdateLayout() 
+    self:ensurePanelsRelSize() 
+end
+
+function BugDemoWindow:onInput(keys)
+    local key_info = {}
+    for key, value in pairs(keys) do
+        table.insert(key_info, string.format("%s=%s", tostring(key), tostring(value)))
+    end
+
+    table.sort(key_info)
+
+    return BugDemoWindow.super.onInput(self, keys)
+end
+
+function BugDemoScreen:init()
+    local optimal_size = self:calculateOptimalFrameSize()
+    self:addviews{BugDemoWindow {frame = optimal_size}}
+end
+
+function BugDemoScreen:calculateOptimalFrameSize()
+    local base_width = 100
+    local base_height = 35
+
+    local optimal_width = math.max(base_width, 90)
+    local optimal_height = math.max(base_height, 25)
+
+    return {w = optimal_width, h = optimal_height}
+end
+
+function BugDemoScreen:onDismiss()
+    bug_demo_screen = nil
+end
+
+bug_demo_screen = bug_demo_screen or nil
+
+if dfhack_flags.module then
+    return
+end
+
+-- Main entry point
+-- if not dfhack.isWorldLoaded() then
+--     qerror("This script requires a loaded world")
+-- end
+
+-- Check for existing instance
+if bug_demo_screen and not bug_demo_screen._native then
+    bug_demo_screen = nil
+end
+
+if bug_demo_screen then
+    local success, is_dismissed = pcall(function()
+        return bug_demo_screen:isDismissed()
+    end)
+    if not success or is_dismissed then
+        bug_demo_screen = nil
+    else
+        return
+    end
+end
+
+-- Create and show new instance
+bug_demo_screen = BugDemoScreen{}:show()