implement panel resizing

docs/dev/Lua API.rst

@@ -4182,9 +4182,28 @@ Has attributes:
   ``true`` if the drag was "successful" (i.e. not canceled) and ``false``
   otherwise. Dragging can be canceled by right clicking while dragging with the
   mouse, hitting :kbd:`Esc` (while dragging with the mouse or keyboard), or by
-  calling ``Panel:setCursorMoveEnabled(false)`` (while dragging with the
+  calling ``Panel:setKeyboaredDragEnabled(false)`` (while dragging with the
   keyboard).
 
+* ``resizable = bool`` (default: ``false``)
+* ``resize_anchors = {}`` (default: ``{t=false, l=true, r=true, b=true}``
+* ``resize_min = {}`` (default: w and h from the ``frame``, or ``{w=5, h=5}``)
+* ``on_resize_begin = function()`` (default: ``nil``)
+* ``on_resize_end = function(bool)`` (default: ``nil``)
+
+  If ``resizable`` is set to ``true``, then the player can click the mouse on
+  any edge specified in ``resize_anchors`` and drag the border to resize the
+  window. If two adjacent edges are enabled as anchors, then the tile where they
+  meet can be used to resize both edges at the same time. The minimum dimensions
+  specified in ``resize_min`` (or inherited from ``frame`` are respected when
+  resizing. The panel is also prevented from resizing beyond the boundaries of
+  its parent. When the player clicks on a valid anchor, ``on_resize_begin()`` is
+  called. The boolean passed to the ``on_resize_end`` callback will be ``true``
+  if the drag was "successful" (i.e. not canceled) and ``false`` otherwise.
+  Dragging can be canceled by right clicking while resizing with the mouse,
+  hitting :kbd:`Esc` (while resizing with the mouse or keyboard), or by calling
+  ``Panel:setKeyboardResizeEnabled(false)`` (while resizing with the keyboard).
+
 * ``autoarrange_subviews = bool`` (default: ``false``)
 * ``autoarrange_gap = int`` (default: ``0``)
 
@@ -4207,8 +4226,8 @@ Has functions:
 
 * ``panel:setKeyboardDragEnabled(bool)``
 
-  If called with something truthy and the panel is not already in keyboard drag
-  mode, then any current drag operations are halted where they are (not
+  If called with ``true`` and the panel is not already in keyboard drag mode,
+  then any current drag or resize operations are halted where they are (not
   canceled), the panel siezes input focus (see `View class`_ above for
   information on the DFHack focus subsystem), and further keyboard cursor keys
   move the window as if it were being dragged. Shift-cursor keys move by larger
@@ -4216,12 +4235,24 @@ Has functions:
   cancel. If dragging is canceled, then the window is moved back to its original
   position.
 
+* ``panel:setKeyboardResizeEnabled(bool)``
+
+  If called with ``true`` and the panel is not already in keyboard resize mode,
+  then any current drag or resize operations are halted where they are (not
+  canceled), the panel siezes input focus (see `View class`_ above for
+  information on the DFHack focus subsystem), and further keyboard cursor keys
+  resize the window as if it were being dragged from the lower right corner. If
+  neither the bottom or right edge is a valid anchor, an appropriate corner will
+  be chosen. Shift-cursor keys move by larger amounts. Hit :kbd:`Enter` to
+  commit the new window size or :kbd:`Esc` to cancel. If resizing is canceled,
+  then the window size from before the resize operation is restored.
+
 ResizingPanel class
 -------------------
 
-Subclass of Panel; automatically adjusts its own frame height according to
-the size, position, and visibility of its subviews. Pairs nicely with a
-parent Panel that has ``autoarrange_subviews`` enabled.
+Subclass of Panel; automatically adjusts its own frame height and width to the
+minimum required to show its subviews. Pairs nicely with a parent Panel that has
+``autoarrange_subviews`` enabled.
 
 Pages class
 -----------

library/lua/gui/widgets.lua

@@ -76,24 +76,35 @@ Panel.ATTRS {
     drag_bound = 'frame', -- or 'body'
     on_drag_begin = DEFAULT_NIL,
     on_drag_end = DEFAULT_NIL,
+    resizable = false,
+    resize_anchors = {t=false, l=true, r=true, b=true},
+    resize_min = DEFAULT_NIL,
+    on_resize_begin = DEFAULT_NIL,
+    on_resize_end = DEFAULT_NIL,
     autoarrange_subviews = false, -- whether to automatically lay out subviews
     autoarrange_gap = 0, -- how many blank lines to insert between widgets
 }
 
 function Panel:init(args)
-    self.keyboard_drag = nil -- true when we are in keyboard dragging mode
+    self.resize_min = self.resize_min or {}
+    self.resize_min.w = self.resize_min.w or (self.frame or {}).w or 5
+    self.resize_min.h = self.resize_min.h or (self.frame or {}).h or 5
+
+    self.kbd_get_pos = nil -- fn when we are in keyboard dragging mode
     self.saved_frame = nil -- copy of frame when dragging started
     self.saved_frame_rect = nil -- copy of frame_rect when dragging started
     self.drag_offset = nil -- relative pos of held panel tile
+    self.resize_edge = nil -- which dimension is being resized?
     self:addviews(args.subviews)
 end
 
 local function Panel_update_frame(self, frame, clear_state)
     if clear_state then
-        self.keyboard_drag = nil
+        self.kbd_get_pos = nil
         self.saved_frame = nil
         self.saved_frame_rect = nil
         self.drag_offset = nil
+        self.resize_edge = nil
     end
     if not frame then return end
     if self.frame.l == frame.l and self.frame.r == frame.r
@@ -105,6 +116,57 @@ local function Panel_update_frame(self, frame, clear_state)
     self:updateLayout()
 end
 
+-- dim: the name of the dimension var (i.e. 'h' or 'w')
+-- anchor: the name of the anchor var (i.e. 't', 'b', 'l', or 'r')
+-- opposite_anchor: the name of the anchor var for the opposite edge
+-- max_dim: how big this panel can get from its current pos and fit in parent
+-- wanted_dim: how big the player is trying to make the panel
+-- max_anchor: max value of the frame anchor for the edge that is being resized
+-- wanted_anchor: how small the player is trying to make the anchor value
+local function Panel_resize_edge_base(frame, resize_min, dim, anchor,
+                                      opposite_anchor, max_dim, wanted_dim,
+                                      max_anchor, wanted_anchor)
+    frame[dim] = math.max(resize_min[dim], math.min(max_dim, wanted_dim))
+    if frame[anchor] or not frame[opposite_anchor] then
+        frame[anchor] = math.max(0, math.min(max_anchor, wanted_anchor))
+    end
+end
+
+local function Panel_resize_edge(frame, resize_min, dim, anchor,
+                                 opposite_anchor, dim_base, dim_ref, anchor_ref,
+                                 dim_far, mouse_ref)
+    local dim_sign = (anchor == 't' or anchor == 'l') and 1 or -1
+    local max_dim = dim_base - dim_ref + 1
+    local wanted_dim = dim_sign * (dim_far - mouse_ref) + 1
+    local max_anchor = dim_base - resize_min[dim] - dim_ref + 1
+    local wanted_anchor = dim_sign * (mouse_ref - anchor_ref)
+    Panel_resize_edge_base(frame, resize_min, dim, anchor, opposite_anchor,
+                           max_dim, wanted_dim, max_anchor, wanted_anchor)
+end
+
+local function Panel_resize_frame(self, mouse_pos)
+    local frame, resize_min = copyall(self.frame), self.resize_min
+    local parent_rect = self.frame_parent_rect
+    local ref_rect = self.saved_frame_rect
+    if self.resize_edge:find('t') then
+        Panel_resize_edge(frame, resize_min, 'h', 't', 'b', ref_rect.y2,
+                    parent_rect.y1, parent_rect.y1, ref_rect.y2, mouse_pos.y)
+    end
+    if self.resize_edge:find('b') then
+        Panel_resize_edge(frame, resize_min, 'h', 'b', 't', parent_rect.y2,
+                          ref_rect.y1, parent_rect.y2, ref_rect.y1, mouse_pos.y)
+    end
+    if self.resize_edge:find('l') then
+        Panel_resize_edge(frame, resize_min, 'w', 'l', 'r', ref_rect.x2,
+                    parent_rect.x1, parent_rect.x1, ref_rect.x2, mouse_pos.x)
+    end
+    if self.resize_edge:find('r') then
+        Panel_resize_edge(frame, resize_min, 'w', 'r', 'l', parent_rect.x2,
+                          ref_rect.x1, parent_rect.x2, ref_rect.x1, mouse_pos.x)
+    end
+    return frame
+end
+
 local function Panel_drag_frame(self, mouse_pos)
     local frame = copyall(self.frame)
     local parent_rect, frame_rect = self.frame_parent_rect, self.frame_rect
@@ -140,31 +202,42 @@ end
 
 local function Panel_make_frame(self, mouse_pos)
     mouse_pos = mouse_pos or xy2pos(dfhack.screen.getMousePos())
-    return Panel_drag_frame(self, mouse_pos)
+    return self.resize_edge and Panel_resize_frame(self, mouse_pos)
+            or Panel_drag_frame(self, mouse_pos)
 end
 
-local function Panel_begin_drag(self, drag_offset)
+local function Panel_begin_drag(self, drag_offset, resize_edge)
     Panel_update_frame(self, nil, true)
     self.drag_offset = drag_offset or {x=0, y=0}
+    self.resize_edge = resize_edge
     self.saved_frame = copyall(self.frame)
     self.saved_frame_rect = copyall(self.frame_rect)
     self.prev_focus_owner = self.focus_group.cur
     self:setFocus(true)
-    if self.on_drag_begin then self.on_drag_begin() end
+    if self.resize_edge then
+        if self.on_resize_begin then self.on_resize_begin(success) end
+    else
+        if self.on_drag_begin then self.on_drag_begin(success) end
+    end
 end
 
 local function Panel_end_drag(self, frame, success)
+    success = not not success
     if self.prev_focus_owner then
         self.prev_focus_owner:setFocus(true)
     else
         self:setFocus(false)
     end
     Panel_update_frame(self, frame, true)
-    if self.on_drag_end then self.on_drag_end(success) end
+    if self.resize_edge then
+        if self.on_resize_end then self.on_resize_end(success) end
+    else
+        if self.on_drag_end then self.on_drag_end(success) end
+    end
 end
 
 function Panel:onInput(keys)
-    if self.keyboard_drag then
+    if self.kbd_get_pos then
         if keys.SELECT or keys.LEAVESCREEN then
             Panel_end_drag(self, keys.LEAVESCREEN and self.saved_frame or nil,
                            not not keys.SELECT)
@@ -173,8 +246,10 @@ function Panel:onInput(keys)
         for code in pairs(keys) do
             local dx, dy = guidm.get_movement_delta(code, 1, 10)
             if dx then
-                local kbd_pos = {x=self.frame_rect.x1+dx,
-                                 y=self.frame_rect.y1+dy}
+                local frame_rect = self.frame_rect
+                local kbd_pos = self.kbd_get_pos()
+                kbd_pos.x = kbd_pos.x + dx
+                kbd_pos.y = kbd_pos.y + dy
                 Panel_update_frame(self, Panel_make_frame(self, kbd_pos))
                 return true
             end
@@ -197,31 +272,74 @@ function Panel:onInput(keys)
     local x,y = self:getMousePos(gui.ViewRect{rect=rect})
     if not x then return end
 
+    if self.resizable then
+        local rect = self.frame_rect
+        if self.resize_anchors.r and self.resize_anchors.b
+                and x == rect.x2 - rect.x1 and y == rect.y2 - rect.y1 then
+            self.resize_edge = 'rb'
+        elseif self.resize_anchors.l and self.resize_anchors.b
+                and x == 0 and y == rect.y2 - rect.y1 then
+            self.resize_edge = 'lb'
+        elseif self.resize_anchors.r and self.resize_anchors.t
+                and x == rect.x2 - rect.x1 and y == 0 then
+            self.resize_edge = 'rt'
+        elseif self.resize_anchors.r and self.resize_anchors.t
+                and x == 0 and y == 0 then
+            self.resize_edge = 'lt'
+        elseif self.resize_anchors.r and x == rect.x2 - rect.x1 then
+            self.resize_edge = 'r'
+        elseif self.resize_anchors.l and x == 0 then
+            self.resize_edge = 'l'
+        elseif self.resize_anchors.b and y == rect.y2 - rect.y1 then
+            self.resize_edge = 'b'
+        elseif self.resize_anchors.t and y == 0 then
+            self.resize_edge = 't'
+        end
+    end
+
     local is_dragging = false
-    if self.draggable then
+    if not self.resize_edge and self.draggable then
         local on_body = self:getMousePos()
         is_dragging = (self.drag_anchors.title and self.frame_style and y == 0)
                 or (self.drag_anchors.frame and not on_body) -- includes inset
                 or (self.drag_anchors.body and on_body)
     end
 
-    if is_dragging then
-        Panel_begin_drag(self, {x=x, y=y})
+    if self.resize_edge or is_dragging then
+        Panel_begin_drag(self, {x=x, y=y}, self.resize_edge)
         return true
     end
 end
 
 function Panel:setKeyboardDragEnabled(enabled)
-    if (enabled and self.keyboard_drag)
-            or (not enabled and not self.keyboard_drag) then
+    if (enabled and self.kbd_get_pos)
+            or (not enabled and not self.kbd_get_pos) then
+        return
+    end
+    if enabled then
+        local kbd_get_pos = function() return {x=0, y=0} end
+        Panel_begin_drag(self, kbd_get_pos())
+        self.kbd_get_pos = kbd_get_pos
+    else
+        Panel_end_drag(self)
+    end
+end
+
+function Panel:setKeyboardResizeEnabled(enabled)
+    if (enabled and self.kbd_get_pos)
+            or (not enabled and not self.kbd_get_pos) then
         return
     end
     if enabled then
-        Panel_begin_drag(self)
+        local resize_edge = 'rb'
+        local kbd_get_pos = function()
+            return {x=self.frame_rect.x2, y=self.frame_rect.y2}
+        end
+        Panel_begin_drag(self, kbd_get_pos(), resize_edge)
+        self.kbd_get_pos = kbd_get_pos
     else
         Panel_end_drag(self)
     end
-    self.keyboard_drag = enabled
 end
 
 function Panel:onRenderBody(dc)
@@ -264,7 +382,7 @@ function Panel:onRenderFrame(dc, rect)
     if not self.frame_style then return end
     local x1,y1,x2,y2 = rect.x1, rect.y1, rect.x2, rect.y2
     gui.paint_frame(x1, y1, x2, y2, self.frame_style, self.frame_title)
-    if self.drag_offset and not self.keyboard_drag
+    if self.drag_offset and not self.kbd_get_pos
             and df.global.enabler.mouse_lbut == 0 then
         Panel_end_drag(self, nil, true)
     end