Fluid: restructuring and rejuvenation of the source code.

* Add classes for application and project
* Removed all globals from Fluid.h
* Extracting args and project history into their own classes
* Moving globals into Application class
* Initialize values inside headers for some classes.
* Undo functionality wrapped in a class inside Project.
* File reader and writer are now linked to a project.
* Avoid global project access
* Nodes (former Types) will be managed by a new Tree class.
* Removed static members (hidden globals) form Node/Fl_Type.
* Adding Tree iterator.
* Use nullptr instead of 0, NULL, or 0L
* Renamed Fl_..._Type to ..._Node, FL_OVERRIDE -> override
* Renaming ..._type to ...::prototype
* Splitting Widget Panel into multiple files.
* Moved callback code into widget panel file.
* Cleaning up Fluid_Image -> Image_asset
* Moving Fd_Snap_Action into new namespace fld::app::Snap_Action etc.
* Moved mergeback into proj folder.
* `enum ID` is now `enum class Type`.

1 files changed, 414 insertions, 0 deletions

diff --git a/fluid/proj/align_widget.cxx b/fluid/proj/align_widget.cxx
new file mode 100644
index 000000000..9ce9e2b62
--- /dev/null
+++ b/fluid/proj/align_widget.cxx
@@ -0,0 +1,414 @@
+//
+// Alignment code for the Fast Light Tool Kit (FLTK).
+//
+// Copyright 1998-2025 by Bill Spitzak and others.
+//
+// This library is free software. Distribution and use rights are outlined in
+// the file "COPYING" which should have been included with this file.  If this
+// file is missing or damaged, see the license at:
+//
+//     https://www.fltk.org/COPYING.php
+//
+// Please see the following page on how to report bugs and issues:
+//
+//     https://www.fltk.org/bugs.php
+//
+
+#include "proj/align_widget.h"
+
+#include "Fluid.h"
+#include "proj/undo.h"
+#include "nodes/Group_Node.h"
+
+#include <FL/Fl.H>
+#include <FL/Fl_Window.H>
+
+/**
+ the first behavior always uses the first selected widget as a reference
+ the second behavior uses the largest widget (most extreme positions) as
+ a reference.
+ */
+#define BREAK_ON_FIRST break
+//#define BREAK_ON_FIRST
+
+void align_widget_cb(Fl_Widget*, long how)
+{
+  const int max = 32768, min = -32768;
+  int left, right, top, bot, wdt, hgt, n;
+  Node *o;
+  int changed = 0;
+  switch ( how )
+  {
+  //---- align
+  case 10: // align left
+    left = max;
+    for (o = Fluid.proj.tree.first; o; o = o->next)
+      if (o->selected && o->is_widget())
+      {
+        Fl_Widget *w = ((Widget_Node *)o)->o;
+        if (w->x()<left)
+          left = w->x();
+        BREAK_ON_FIRST;
+      }
+    if (left!=max)
+      for (Node *o = Fluid.proj.tree.first; o; o = o->next)
+        if (o->selected && o->is_widget())
+        {
+          if (!changed) {
+            changed = 1;
+            Fluid.proj.undo.checkpoint();
+          }
+          Fl_Widget *w = ((Widget_Node *)o)->o;
+          Fluid.proj.tree.allow_layout++;
+          w->resize(left, w->y(), w->w(), w->h());
+          Fluid.proj.tree.allow_layout--;
+          w->redraw();
+          if (w->window()) w->window()->redraw();
+        }
+    break;
+  case 11: // align h.center
+    left = max; right = min;
+    for (o = Fluid.proj.tree.first; o; o = o->next)
+      if (o->selected && o->is_widget())
+      {
+        Fl_Widget *w = ((Widget_Node *)o)->o;
+        if (w->x()<left)
+          left = w->x();
+        if (w->x()+w->w()>right)
+          right = w->x()+w->w();
+        BREAK_ON_FIRST;
+      }
+    if (left!=max)
+    {
+      int center2 = left+right;
+      for (Node *o = Fluid.proj.tree.first; o; o = o->next)
+        if (o->selected && o->is_widget())
+        {
+          if (!changed) {
+            changed = 1;
+            Fluid.proj.undo.checkpoint();
+          }
+          Fl_Widget *w = ((Widget_Node *)o)->o;
+          Fluid.proj.tree.allow_layout++;
+          w->resize((center2-w->w())/2, w->y(), w->w(), w->h());
+          Fluid.proj.tree.allow_layout--;
+          w->redraw();
+          if (w->window()) w->window()->redraw();
+        }
+    }
+    break;
+  case 12: // align right
+    right = min;
+    for (o = Fluid.proj.tree.first; o; o = o->next)
+      if (o->selected && o->is_widget())
+      {
+        Fl_Widget *w = ((Widget_Node *)o)->o;
+        if (w->x()+w->w()>right)
+          right = w->x()+w->w();
+        BREAK_ON_FIRST;
+      }
+    if (right!=min)
+      for (Node *o = Fluid.proj.tree.first; o; o = o->next)
+        if (o->selected && o->is_widget())
+        {
+          if (!changed) {
+            changed = 1;
+            Fluid.proj.undo.checkpoint();
+          }
+          Fl_Widget *w = ((Widget_Node *)o)->o;
+          Fluid.proj.tree.allow_layout++;
+          w->resize(right-w->w(), w->y(), w->w(), w->h());
+          Fluid.proj.tree.allow_layout--;
+          w->redraw();
+          if (w->window()) w->window()->redraw();
+        }
+    break;
+  case 13: // align top
+    top = max;
+    for (o = Fluid.proj.tree.first; o; o = o->next)
+      if (o->selected && o->is_widget())
+      {
+        Fl_Widget *w = ((Widget_Node *)o)->o;
+        if (w->y()<top)
+          top = w->y();
+        BREAK_ON_FIRST;
+      }
+    if (top!=max)
+      for (Node *o = Fluid.proj.tree.first; o; o = o->next)
+        if (o->selected && o->is_widget())
+        {
+          if (!changed) {
+            changed = 1;
+            Fluid.proj.undo.checkpoint();
+          }
+          Fl_Widget *w = ((Widget_Node *)o)->o;
+          Fluid.proj.tree.allow_layout++;
+          w->resize(w->x(), top, w->w(), w->h());
+          Fluid.proj.tree.allow_layout--;
+          w->redraw();
+          if (w->window()) w->window()->redraw();
+        }
+    break;
+  case 14: // align v.center
+    top = max; bot = min;
+    for (o = Fluid.proj.tree.first; o; o = o->next)
+      if (o->selected && o->is_widget())
+      {
+        Fl_Widget *w = ((Widget_Node *)o)->o;
+        if (w->y()<top)
+          top = w->y();
+        if (w->y()+w->h()>bot)
+          bot = w->y()+w->h();
+        BREAK_ON_FIRST;
+      }
+    if (top!=max)
+    {
+      int center2 = top+bot;
+      for (Node *o = Fluid.proj.tree.first; o; o = o->next)
+        if (o->selected && o->is_widget())
+        {
+          if (!changed) {
+            changed = 1;
+            Fluid.proj.undo.checkpoint();
+          }
+          Fl_Widget *w = ((Widget_Node *)o)->o;
+          Fluid.proj.tree.allow_layout++;
+          w->resize(w->x(), (center2-w->h())/2, w->w(), w->h());
+          Fluid.proj.tree.allow_layout--;
+          w->redraw();
+          if (w->window()) w->window()->redraw();
+        }
+    }
+    break;
+  case 15: // align bottom
+    bot = min;
+    for (o = Fluid.proj.tree.first; o; o = o->next)
+      if (o->selected && o->is_widget())
+      {
+        Fl_Widget *w = ((Widget_Node *)o)->o;
+        if (w->y()+w->h()>bot)
+          bot = w->y()+w->h();
+        BREAK_ON_FIRST;
+      }
+    if (bot!=min)
+      for (Node *o = Fluid.proj.tree.first; o; o = o->next)
+        if (o->selected && o->is_widget())
+        {
+          if (!changed) {
+            changed = 1;
+            Fluid.proj.undo.checkpoint();
+          }
+          Fl_Widget *w = ((Widget_Node *)o)->o;
+          Fluid.proj.tree.allow_layout++;
+          w->resize( w->x(), bot-w->h(), w->w(), w->h());
+          Fluid.proj.tree.allow_layout--;
+          w->redraw();
+          if (w->window()) w->window()->redraw();
+        }
+    break;
+  //---- space evenly
+  case 20: // space evenly across
+    left = max; right = min; wdt = 0; n = 0;
+    for (o = Fluid.proj.tree.first; o; o = o->next)
+      if (o->selected && o->is_widget())
+      {
+        Fl_Widget *w = ((Widget_Node *)o)->o;
+        if (w->x()<left)
+          left = w->x();
+        if (w->x()+w->w()>right)
+          right = w->x()+w->w();
+        wdt += w->w();
+        n++;
+      }
+    wdt = (right-left)-wdt;
+    n--;
+    if (n>0)
+    {
+      wdt = wdt/n*n; // make sure that all gaps are the same, possibly moving the rightmost widget
+      int cnt = 0, wsum = 0;
+      for (Node *o = Fluid.proj.tree.first; o; o = o->next)
+        if (o->selected && o->is_widget())
+        {
+          if (!changed) {
+            changed = 1;
+            Fluid.proj.undo.checkpoint();
+          }
+          Fl_Widget *w = ((Widget_Node *)o)->o;
+          Fluid.proj.tree.allow_layout++;
+          w->resize(left+wsum+wdt*cnt/n, w->y(), w->w(), w->h());
+          Fluid.proj.tree.allow_layout--;
+          w->redraw();
+          if (w->window()) w->window()->redraw();
+          cnt++;
+          wsum += w->w();
+        }
+    }
+    break;
+  case 21: // space evenly down
+    top = max; bot = min; hgt = 0, n = 0;
+    for (o = Fluid.proj.tree.first; o; o = o->next)
+      if (o->selected && o->is_widget())
+      {
+        Fl_Widget *w = ((Widget_Node *)o)->o;
+        if (w->y()<top)
+          top = w->y();
+        if (w->y()+w->h()>bot)
+          bot = w->y()+w->h();
+        hgt += w->h();
+        n++;
+      }
+    hgt = (bot-top)-hgt;
+    n--;
+    if (n>0)
+    {
+      hgt = hgt/n*n; // make sure that all gaps are the same, possibly moving the rightmost widget
+      int cnt = 0, hsum = 0;
+      for (Node *o = Fluid.proj.tree.first; o; o = o->next)
+        if (o->selected && o->is_widget())
+        {
+          if (!changed) {
+            changed = 1;
+            Fluid.proj.undo.checkpoint();
+          }
+          Fl_Widget *w = ((Widget_Node *)o)->o;
+          Fluid.proj.tree.allow_layout++;
+          w->resize(w->x(), top+hsum+hgt*cnt/n, w->w(), w->h());
+          Fluid.proj.tree.allow_layout--;
+          w->redraw();
+          if (w->window()) w->window()->redraw();
+          cnt++;
+          hsum += w->h();
+        }
+    }
+    break;
+  //---- make same size
+  case 30: // same width
+    wdt = min;
+    for (o = Fluid.proj.tree.first; o; o = o->next)
+      if (o->selected && o->is_widget())
+      {
+        Fl_Widget *w = ((Widget_Node *)o)->o;
+        if (w->w()>wdt)
+          wdt = w->w();
+        BREAK_ON_FIRST;
+      }
+    if (wdt!=min)
+      for (Node *o = Fluid.proj.tree.first; o; o = o->next)
+        if (o->selected && o->is_widget())
+        {
+          if (!changed) {
+            changed = 1;
+            Fluid.proj.undo.checkpoint();
+          }
+          Fl_Widget *w = ((Widget_Node *)o)->o;
+          Fluid.proj.tree.allow_layout++;
+          w->resize(w->x(), w->y(), wdt, w->h());
+          Fluid.proj.tree.allow_layout--;
+          w->redraw();
+          if (w->window()) w->window()->redraw();
+        }
+    break;
+  case 31: // same height
+    hgt = min;
+    for (o = Fluid.proj.tree.first; o; o = o->next)
+      if (o->selected && o->is_widget())
+      {
+        Fl_Widget *w = ((Widget_Node *)o)->o;
+        if (w->h()>hgt)
+          hgt = w->h();
+        BREAK_ON_FIRST;
+      }
+    if (hgt!=min)
+      for (Node *o = Fluid.proj.tree.first; o; o = o->next)
+        if (o->selected && o->is_widget())
+        {
+          if (!changed) {
+            changed = 1;
+            Fluid.proj.undo.checkpoint();
+          }
+          Fl_Widget *w = ((Widget_Node *)o)->o;
+          Fluid.proj.tree.allow_layout++;
+          w->resize( w->x(), w->y(), w->w(), hgt);
+          Fluid.proj.tree.allow_layout--;
+          w->redraw();
+          if (w->window()) w->window()->redraw();
+        }
+    break;
+  case 32: // same size
+    hgt = min; wdt = min;
+    for (o = Fluid.proj.tree.first; o; o = o->next)
+      if (o->selected && o->is_widget())
+      {
+        Fl_Widget *w = ((Widget_Node *)o)->o;
+        if (w->w()>wdt)
+          wdt = w->w();
+        if (w->h()>hgt)
+          hgt = w->h();
+        BREAK_ON_FIRST;
+      }
+    if (hgt!=min)
+      for (Node *o = Fluid.proj.tree.first; o; o = o->next)
+        if (o->selected && o->is_widget())
+        {
+          if (!changed) {
+            changed = 1;
+            Fluid.proj.undo.checkpoint();
+          }
+          Fl_Widget *w = ((Widget_Node *)o)->o;
+          Fluid.proj.tree.allow_layout++;
+          w->resize( w->x(), w->y(), wdt, hgt);
+          Fluid.proj.tree.allow_layout--;
+          w->redraw();
+          if (w->window()) w->window()->redraw();
+        }
+    break;
+  //---- center in group
+  case 40: // center hor
+    for (o = Fluid.proj.tree.first; o; o = o->next)
+      if (o->selected && o->is_widget() && o->parent)
+      {
+        if (!changed) {
+          changed = 1;
+          Fluid.proj.undo.checkpoint();
+        }
+        Fl_Widget *w = ((Widget_Node *)o)->o;
+        Fl_Widget *p = ((Widget_Node *)o->parent)->o;
+        int center2;
+
+        if (w->window() == p) center2 = p->w();
+        else center2 = 2*p->x()+p->w();
+
+        Fluid.proj.tree.allow_layout++;
+        w->resize((center2-w->w())/2, w->y(), w->w(), w->h());
+        Fluid.proj.tree.allow_layout--;
+        w->redraw();
+        if (w->window()) w->window()->redraw();
+      }
+    break;
+  case 41: // center vert
+    for (o = Fluid.proj.tree.first; o; o = o->next)
+      if (o->selected && o->is_widget() && o->parent)
+      {
+        if (!changed) {
+          changed = 1;
+          Fluid.proj.undo.checkpoint();
+        }
+        Fl_Widget *w = ((Widget_Node *)o)->o;
+        Fl_Widget *p = ((Widget_Node *)o->parent)->o;
+        int center2;
+
+        if (w->window() == p) center2 = p->h();
+        else center2 = 2*p->y()+p->h();
+
+        Fluid.proj.tree.allow_layout++;
+        w->resize(w->x(), (center2-w->h())/2, w->w(), w->h());
+        Fluid.proj.tree.allow_layout--;
+        Fluid.proj.set_modflag(1);
+        w->redraw();
+        if (w->window()) w->window()->redraw();
+      }
+    break;
+  }
+  if (changed)
+    Fluid.proj.set_modflag(1);
+}