How to organize complex programs?

[Vida Marcell]

For example, if someone makes a 3d modeling software, how is he going to separate the front-end code form back-end code. I always coded UAK apps in one file, and now its getting complex, i want to have a 3d viewer in one of the panels, and i already got the ui, but i dont want to write everything in one cpp file.

[SpiderPig]

 You can separate each class into their own CPP and H files and then include them into your Main.cpp.

[Josh]

I use this as my base class and make derived classes for each major part of a program, usually a window or some panel with a lot of controls on it. You can listen for a specific widget and evaluate everything that happens in ProcessEvent():

UIElement.hUIElement.cpp

[Josh]

Here is an example of a derived class. I create a panel for the area of the interface this is creating, and add all the widgets it uses. For any widgets it uses, I call Listen() so those events will get evaluated by ProcessEvent(), where they are all handled:

AboutWindow.h

#pragma once
#include "UltraEngine.h"
#include "../Editor.h"

class AboutWindow : public UIElement
{
public:
	shared_ptr<Window> window;
	shared_ptr<Widget> closebutton;
	virtual bool Initialize(shared_ptr<Window> parent);
	virtual bool ProcessEvent(const Event& e);
};

AboutWindow.cpp

#pragma once
#include "UltraEngine.h"
#include "../Editor.h"

bool AboutWindow::Initialize(shared_ptr<Window> parent)
{
	int statusheight = 40;
	iVec2 size = iVec2(600,380);
	window = CreateWindow("",0,0,size.x,size.y,parent,WINDOW_CENTER | WINDOW_TITLEBAR | WINDOW_HIDDEN);
	auto ui = CreateInterface(window);
	//ui->root->SetColor(0, 0, 0, 1);
	auto panel = CreatePanel(0,0,ui->root->size.x,ui->root->size.y-statusheight,ui->root, PANEL_BORDER);
	panel->SetColor(panel->color[WIDGETCOLOR_SUNKEN]);
	panel->SetLayout(1, 1, 1, 1);
	WString apptitle, appversion;
	apptitle = JSONGetString(editor->config["appTitle"]);
	appversion = JSONGetString(editor->config["appVersion"]);
	auto label = CreateLabel(apptitle + " " + appversion + "\nCopyright Ultra Software 2021", 4, 0 + ui->root->ClientSize().y - statusheight, panel->ClientSize().x, statusheight, ui->root, LABEL_MIDDLE);
	label->SetLayout(1, 0, 0, 1);
	label->SetFontScale(editor->smallfontscale);
	label->SetColor(editor->smallfontcolor, WIDGETCOLOR_FOREGROUND);
	auto logopanel = CreatePanel(0, panel->size.y / 2 - 40, panel->size.x*0.6, 60, panel);
	auto logo = LoadIcon("Icons/UltraEngine.svg");
	auto logop = logo->Rasterize(0.4);
	logopanel->SetPixmap(logop);
	auto splash = LoadPixmap("splashscreen.dds",0,0,LOAD_QUIET);
	panel->SetPixmap(splash,PIXMAP_COVER);
	logopanel->SetColor(1, 1, 1, 0);
	auto link = CreateHyperlink(JSONGetString(editor->config["url"]), ui->root->size.x - 150 - 4, ui->root->size.y - statusheight, 150, statusheight, ui->root, LABEL_MIDDLE | LABEL_RIGHT);
	link->SetLayout(0, 1, 0, 1);
	link->SetFontScale(editor->smallfontscale);
	link->SetColor(editor->smallfontcolor, WIDGETCOLOR_FOREGROUND);
	closebutton = CreateButton("Close",-200,-200,100,100,ui->root,BUTTON_CANCEL);
  
  	//Listen for events
	Listen(EVENT_WIDGETACTION, closebutton);
	Listen(EVENT_WINDOWCLOSE, window);
  
  	//Rescale interface
	if (parent->display->scale != 1.0f)
	{
		size.x = window->size.x * parent->display->scale;
		size.y = window->size.y * parent->display->scale;
		window->SetShape((parent->display->size.x - size.x)/2, (parent->display->size.y - size.y)/2,size.x,size.y);
		ui->SetScale(parent->display->scale);
	}
	return true;
}

bool AboutWindow::ProcessEvent(const Event& e)
{
	switch (e.id)
	{
	case EVENT_WIDGETACTION:
		if (e.source == closebutton)
		{
			EmitEvent(EVENT_WINDOWCLOSE, window);
		}
		break;
	case EVENT_WINDOWCLOSE:
		if (e.source == window)
		{
			window->GetParent()->Activate();
			window->SetHidden(true);
		}
		break;
	}
	return true;
}