implement dear imgui settings handler to save window-open state

src/CMakeLists.txt

@@ -33,6 +33,7 @@ set(SOURCES
     asm.c asm.h
     ui.cc ui.h
     ui_asm.cc ui_asm.h
+    imgui_util.cc imgui_util.h
     common.h
 )
 

src/imgui_util.cc

@@ -0,0 +1,64 @@
+#include "imgui.h"
+#include "imgui_internal.h"
+#include "imgui_util.h"
+#include "ui.h"
+#include "util.h"
+
+static void imgui_ClearAllFn(ImGuiContext* ctx, ImGuiSettingsHandler* handler) {
+    (void)ctx; (void)handler;
+}
+
+// read: Called before reading (in registration order)
+static void imgui_ReadInitFn(ImGuiContext* ctx, ImGuiSettingsHandler* handler) {
+    (void)ctx; (void)handler;
+}
+
+// read: Called when entering into a new ini entry e.g. "[Window][Name]"
+static void* imgui_ReadOpenFn(ImGuiContext* ctx, ImGuiSettingsHandler* handler, const char* name) {
+    (void)ctx; (void)handler;
+    return (void*)ui_window_by_id(name);
+}
+
+// read: Called for every line of text within an ini entry
+static void imgui_ReadLineFn(ImGuiContext* ctx, ImGuiSettingsHandler* handler, void* entry, const char* line) {
+    (void)ctx; (void)handler; (void)entry;
+    ui_window_t win = (ui_window_t)(uintptr_t)entry;
+    if ((win > UI_WINDOW_INVALID) && (win < UI_WINDOW_NUM)) {
+        int is_open = 0;
+        if (sscanf(line, "IsOpen=%i", &is_open) == 1) {
+            ui_init_window_open(win, true);
+        }
+    }
+}
+
+// read: Called after reading (in registration order)
+static void imgui_ApplyAllFn(ImGuiContext* ctx, ImGuiSettingsHandler* handler) {
+    (void)ctx; (void)handler;
+}
+
+// write: output all entries into 'out_buf'
+static void imgui_WriteAllFn(ImGuiContext* ctx, ImGuiSettingsHandler* handler, ImGuiTextBuffer* buf) {
+    (void)ctx; (void)handler;
+    for (int i = UI_WINDOW_INVALID + 1; i < UI_WINDOW_NUM; i++) {
+        ui_window_t win = (ui_window_t)i;
+        buf->appendf("[%s][%s]\n", handler->TypeName, ui_window_id(win));
+        if (ui_is_window_open(win)) {
+            buf->append("IsOpen=1\n");
+        }
+    }
+    buf->append("\n");
+}
+
+void imgui_register_settings_handler(void) {
+    const char* type_name = "floooh.v6502r";
+    ImGuiSettingsHandler ini_handler;
+    ini_handler.TypeName = type_name;;
+    ini_handler.TypeHash = ImHashStr(type_name);
+    ini_handler.ClearAllFn = imgui_ClearAllFn;
+    ini_handler.ReadInitFn = imgui_ReadInitFn;
+    ini_handler.ReadOpenFn = imgui_ReadOpenFn;
+    ini_handler.ReadLineFn = imgui_ReadLineFn;
+    ini_handler.ApplyAllFn = imgui_ApplyAllFn;
+    ini_handler.WriteAllFn = imgui_WriteAllFn;
+    ImGui::AddSettingsHandler(&ini_handler);
+}

src/imgui_util.h

@@ -0,0 +1,11 @@
+#pragma once
+
+#if defined(__cplusplus)
+extern "C" {
+#endif
+
+void imgui_register_settings_handler(void);
+
+#if defined(__cplusplus)
+} // extern "C"
+#endif

src/ui.cc

@@ -34,6 +34,7 @@
 #include "pick.h"
 #include "trace.h"
 #include "util.h"
+#include "imgui_util.h"
 #include "TextEditor.h"
 #include "nodenames.h"
 
@@ -251,36 +252,36 @@ static void ui_ioedit(void);
 static ImGui::MarkdownConfig md_conf;
 
 void ui_check_dirty(ui_window_t win) {
-    assert((win >= 0) && (win < UI_WINDOW_NUM));
+    assert((win > UI_WINDOW_INVALID) && (win < UI_WINDOW_NUM));
     if (ui.window_open[win] != ui.prev_window_open[win]) {
         ui.prev_window_open[win] = ui.window_open[win];
         ImGui::MarkIniSettingsDirty();
     }
 }
 
 void ui_init_window_open(ui_window_t win, bool state) {
-    assert((win >= 0) && (win < UI_WINDOW_NUM));
+    assert((win > UI_WINDOW_INVALID) && (win < UI_WINDOW_NUM));
     ui.window_open[win] = state;
     ui.prev_window_open[win] = state;
 }
 
 void ui_set_window_open(ui_window_t win, bool state) {
-    assert((win >= 0) && (win < UI_WINDOW_NUM));
+    assert((win > UI_WINDOW_INVALID) && (win < UI_WINDOW_NUM));
     ui.window_open[win] = state;
 }
 
 bool ui_is_window_open(ui_window_t win) {
-    assert((win >= 0) && (win < UI_WINDOW_NUM));
+    assert((win > UI_WINDOW_INVALID) && (win < UI_WINDOW_NUM));
     return ui.window_open[win];
 }
 
 void ui_toggle_window(ui_window_t win) {
-    assert((win >= 0) && (win < UI_WINDOW_NUM));
+    assert((win > UI_WINDOW_INVALID) && (win < UI_WINDOW_NUM));
     ui.window_open[win] = !ui.window_open[win];
 }
 
 bool* ui_window_open_ptr(ui_window_t win) {
-    assert((win >= 0) && (win < UI_WINDOW_NUM));
+    assert((win > UI_WINDOW_INVALID) && (win < UI_WINDOW_NUM));
     return &ui.window_open[win];
 }
 
@@ -324,7 +325,7 @@ const char* ui_window_name(ui_window_t win) {
 
 ui_window_t ui_window_by_id(const char* id) {
     assert(id);
-    for (int i = 0; i < UI_WINDOW_NUM; i++) {
+    for (int i = UI_WINDOW_INVALID + 1; i < UI_WINDOW_NUM; i++) {
         ui_window_t win = (ui_window_t)i;
         if (0 == strcmp(ui_window_id(win), id)) {
             return win;
@@ -372,6 +373,7 @@ void ui_init() {
     simgui_desc.no_default_font = true;
     simgui_desc.disable_paste_override = true;
     simgui_setup(&simgui_desc);
+    imgui_register_settings_handler();
     auto& style = ImGui::GetStyle();
     style.WindowRounding = 0.0f;
     style.WindowBorderSize = 1.0f;

src/ui.h

@@ -12,7 +12,8 @@ typedef struct {
 } ui_diffview_t;
 
 typedef enum {
-    UI_WINDOW_FLOATING_CONTROLS = 0,
+    UI_WINDOW_INVALID = 0,
+    UI_WINDOW_FLOATING_CONTROLS,    // keep at start
     UI_WINDOW_CPU_CONTROLS,
     UI_WINDOW_TRACELOG,
     UI_WINDOW_TIMING_DIAGRAM,
@@ -31,7 +32,6 @@ typedef enum {
     UI_WINDOW_AUDIO,
     #endif
     UI_WINDOW_NUM,
-    UI_WINDOW_INVALID,
 } ui_window_t;
 
 void ui_init(void);
@@ -41,6 +41,7 @@ void ui_set_window_open(ui_window_t win, bool state);
 void ui_toggle_window(ui_window_t win);
 bool ui_is_window_open(ui_window_t win);
 const char* ui_window_id(ui_window_t win);
+ui_window_t ui_window_by_id(const char* id);
 void ui_check_dirty(ui_window_t win);
 bool* ui_window_open_ptr(ui_window_t win);
 void ui_frame(void);