From 56433308db5715fec88e595601222bb49bf41c76 Mon Sep 17 00:00:00 2001
From: Seth Kingsley <sethk@meowfishies.com>
Date: Wed, 3 Oct 2018 20:23:31 -0700
Subject: [PATCH] Add some RAII wrappers for ImGui calls

---
 extract_raii.rb | 106 ++++++++++++++++++++++++++++++++++++++++++++++++
 imgui_raii.h    |  74 +++++++++++++++++++++++++++++++++
 2 files changed, 180 insertions(+)
 create mode 100644 extract_raii.rb
 create mode 100644 imgui_raii.h

diff --git a/extract_raii.rb b/extract_raii.rb
new file mode 100644
index 000000000..d3a705724
--- /dev/null
+++ b/extract_raii.rb
@@ -0,0 +1,106 @@
+#!/usr/bin/env ruby
+
+$VERBOSE = 2
+
+INDENT = ' ' * 4
+
+puts <<EOT
+#include "imgui.h"
+
+#pragma once
+
+EOT
+
+$current_match = nil
+$class_name = nil
+$pop_body = nil
+
+def close_class
+  pop_body = case $current_match[:name]
+             when 'Begin' then 'if (IsOpen) ImGui::End();'
+             when /^Tree/ then 'if (IsOpen) ImGui::TreePop();'
+             when /^PushID$/ then 'ImGui::PopID();'
+             else fail "Don't know what pop body to use"
+             end
+
+  puts "#{INDENT}~#{$class_name}() { #{pop_body} }"
+
+  if $current_match[:type] == 'bool'
+    puts
+    puts "#{INDENT}operator bool() { return IsOpen; }"
+  end
+
+  puts "};"
+end
+
+header_file = File.open("imgui.h")
+header_file.each_line do |line|
+  line.match(/^\s*IMGUI_API\s+(?<type>[\w\s]+\w)\s+(?<name>\w*)\((?<args>[^)]+)\)(?<attrs>[^;]*);(?<rest>.*)$/) do |m|
+    next unless m[:name].match(/^(Begin|Push|Open|Tree|Column)/)
+    next unless m[:name].match(/^TreeNode|PushID|Begin$/)
+
+    argnames = m[:args].split(/,\s*/).map do |arg|
+      arg = arg.split(/\s*=\s*/, 2).first
+      arg.split(/[ \*]/).last
+    end
+
+    # Check for obsolete
+    if m[:name] == 'Begin' &&
+        (argnames == %w{name p_open size_on_first_use bg_alpha_override flags} ||
+         argnames == %w{items_count items_height})
+      next
+    end
+
+    $stderr.puts m.inspect if $-d
+
+    fail "Return value #{m[:type]} is not bool or void" unless %w{bool void}.include?(m[:type])
+
+    if !$current_match || $current_match[:name] != m[:name]
+      if $current_match
+        close_class
+        puts
+      end
+
+      $current_match = m
+      $class_name = case m[:name]
+                    when 'Begin' then 'ImWindow'
+                    else "Im#{m[:name]}"
+                    end
+
+      puts <<EOT
+class #{$class_name}
+{
+public:
+EOT
+      if m[:type] == 'bool'
+        puts "#{INDENT}#{m[:type]} IsOpen;"
+        puts
+      end
+    end
+
+    attrs = m[:attrs].gsub(/IM_FMT(ARGS|LIST)\(\d+\)/) do |a|
+      a.sub(/\d+/) { |index| (index.to_i + 1).to_s }
+    end
+
+    print "#{INDENT}#{$class_name}(#{m[:args]})#{attrs} { "
+
+    use_varargs = false
+    if argnames.last == '...'
+      argnames[-1] = 'ap'
+      use_varargs = true
+      print "va_list ap; va_start(ap, fmt); "
+    end
+
+    print "IsOpen = " if m[:type] == 'bool'
+
+    print "ImGui::#{m[:name]}"
+    print 'V' if use_varargs
+    print "(#{argnames.join(', ')}); "
+    print 'va_end(ap); ' if use_varargs
+
+    puts '}'
+  end
+end
+
+close_class if $current_match
+
diff --git a/imgui_raii.h b/imgui_raii.h
new file mode 100644
index 000000000..49fe2137e
--- /dev/null
+++ b/imgui_raii.h
@@ -0,0 +1,74 @@
+#include "imgui.h"
+
+#pragma once
+
+class ImWindow
+{
+public:
+    bool IsOpen;
+
+    ImWindow(const char* name, bool* p_open = NULL, ImGuiWindowFlags flags = 0) { IsOpen = ImGui::Begin(name, p_open, flags); }
+    ~ImWindow() { if (IsOpen) ImGui::End(); }
+
+    operator bool() { return IsOpen; }
+};
+
+class ImPushID
+{
+public:
+    ImPushID(const char* str_id) { ImGui::PushID(str_id); }
+    ImPushID(const char* str_id_begin, const char* str_id_end) { ImGui::PushID(str_id_begin, str_id_end); }
+    ImPushID(const void* ptr_id) { ImGui::PushID(ptr_id); }
+    ImPushID(int int_id) { ImGui::PushID(int_id); }
+    ~ImPushID() { ImGui::PopID(); }
+};
+
+class ImTreeNode
+{
+public:
+    bool IsOpen;
+
+    ImTreeNode(const char* label) { IsOpen = ImGui::TreeNode(label); }
+    ImTreeNode(const char* str_id, const char* fmt, ...) IM_FMTARGS(3) { va_list ap; va_start(ap, fmt); IsOpen = ImGui::TreeNodeV(str_id, fmt, ap); va_end(ap); }
+    ImTreeNode(const void* ptr_id, const char* fmt, ...) IM_FMTARGS(3) { va_list ap; va_start(ap, fmt); IsOpen = ImGui::TreeNodeV(ptr_id, fmt, ap); va_end(ap); }
+    ~ImTreeNode() { if (IsOpen) ImGui::TreePop(); }
+
+    operator bool() { return IsOpen; }
+};
+
+class ImTreeNodeV
+{
+public:
+    bool IsOpen;
+
+    ImTreeNodeV(const char* str_id, const char* fmt, va_list args) IM_FMTLIST(3) { IsOpen = ImGui::TreeNodeV(str_id, fmt, args); }
+    ImTreeNodeV(const void* ptr_id, const char* fmt, va_list args) IM_FMTLIST(3) { IsOpen = ImGui::TreeNodeV(ptr_id, fmt, args); }
+    ~ImTreeNodeV() { if (IsOpen) ImGui::TreePop(); }
+
+    operator bool() { return IsOpen; }
+};
+
+class ImTreeNodeEx
+{
+public:
+    bool IsOpen;
+
+    ImTreeNodeEx(const char* label, ImGuiTreeNodeFlags flags = 0) { IsOpen = ImGui::TreeNodeEx(label, flags); }
+    ImTreeNodeEx(const char* str_id, ImGuiTreeNodeFlags flags, const char* fmt, ...) IM_FMTARGS(4) { va_list ap; va_start(ap, fmt); IsOpen = ImGui::TreeNodeExV(str_id, flags, fmt, ap); va_end(ap); }
+    ImTreeNodeEx(const void* ptr_id, ImGuiTreeNodeFlags flags, const char* fmt, ...) IM_FMTARGS(4) { va_list ap; va_start(ap, fmt); IsOpen = ImGui::TreeNodeExV(ptr_id, flags, fmt, ap); va_end(ap); }
+    ~ImTreeNodeEx() { if (IsOpen) ImGui::TreePop(); }
+
+    operator bool() { return IsOpen; }
+};
+
+class ImTreeNodeExV
+{
+public:
+    bool IsOpen;
+
+    ImTreeNodeExV(const char* str_id, ImGuiTreeNodeFlags flags, const char* fmt, va_list args) IM_FMTLIST(4) { IsOpen = ImGui::TreeNodeExV(str_id, flags, fmt, args); }
+    ImTreeNodeExV(const void* ptr_id, ImGuiTreeNodeFlags flags, const char* fmt, va_list args) IM_FMTLIST(4) { IsOpen = ImGui::TreeNodeExV(ptr_id, flags, fmt, args); }
+    ~ImTreeNodeExV() { if (IsOpen) ImGui::TreePop(); }
+
+    operator bool() { return IsOpen; }
+};