// main.cpp

#include <stdio.h>

#include "Application.h"
#include "Message.h"
#include "Button.h"
#include "View.h"
#include "Window.h"

enum {
        MSG_RESET = 'rset'
};

class TestView : public BView {

 public:
                                        TestView(BRect frame, const char* name,
                                                          uint32 resizeFlags, uint32 flags)
                                                : BView(frame, name, resizeFlags, flags),
                                                  fTracking(false),
                                                  fLastMousePos(0.0, 0.0)
                                        {
                                                SetViewUIColor(B_PANEL_BACKGROUND_COLOR);
                                                SetLowUIColor(ViewUIColor());
                                        }

        virtual void    MessageReceived(BMessage* message);

        virtual void    Draw(BRect updateRect);

        virtual void    MouseDown(BPoint where);
        virtual void    MouseUp(BPoint where);
        virtual void    MouseMoved(BPoint where, uint32 transit,
                                                           const BMessage* dragMessage);

 private:
                        bool    fTracking;

                        BPoint  fLastMousePos;
};

// MessageReceived
void
TestView::MessageReceived(BMessage* message)
{
        if (message->what == MSG_RESET)
                ScrollTo(0.0, 0.0);
        else
                BView::MessageReceived(message);
}

// Draw
void
TestView::Draw(BRect updateRect)
{
        // ellipses
        SetHighColor(200, 90, 0, 100);
        StrokeEllipse(BPoint(80.0, 50.0), 70.0, 40.0);

        SetDrawingMode(B_OP_ALPHA);

        SetPenSize(2.0);
        SetHighColor(20, 40, 180, 150);
        StrokeEllipse(BPoint(230.0, 90.0), 14.0, 60.0);

        SetPenSize(5.0);
        SetHighColor(60, 20, 110, 100);
        StrokeEllipse(BPoint(100.0, 180.0), 35.0, 25.0);

        // text
        SetHighColor(0, 0, 0, 255);
        SetDrawingMode(B_OP_OVER);
        const char* message = "Click and drag to scroll this view!";
        DrawString(message, BPoint(0.0, 30.0));
}

// MouseDown
void
TestView::MouseDown(BPoint where)
{
        fTracking = true;
        fLastMousePos = where;
        SetMouseEventMask(B_POINTER_EVENTS);
}

// MouseUp
void
TestView::MouseUp(BPoint where)
{
        fTracking = false;
}

// MouseMoved
void
TestView::MouseMoved(BPoint where, uint32 transit,
                                         const BMessage* dragMessage)
{
        if (fTracking) {
                BPoint offset = fLastMousePos - where;
                ScrollBy(offset.x, offset.y);
                fLastMousePos = where + offset;
        }
}



// show_window
void
show_window(BRect frame, const char* name)
{
        BWindow* window = new BWindow(frame, name,
                                                                  B_TITLED_WINDOW,
                                                                  B_ASYNCHRONOUS_CONTROLS | B_QUIT_ON_WINDOW_CLOSE);

        BView* view = new TestView(window->Bounds(), "test", B_FOLLOW_ALL,
                                                           B_WILL_DRAW/* | B_FULL_UPDATE_ON_RESIZE*/);

        window->AddChild(view);
        BRect b(0.0, 0.0, 60.0, 15.0);
        b.OffsetTo(5.0, view->Bounds().bottom - (b.Height() + 15.0));
        BButton* control = new BButton(b, "button", "Reset", new BMessage(MSG_RESET));
        view->AddChild(control);
        control->SetTarget(view);

        window->Show();
}

// main
int
main(int argc, char** argv)
{
        BApplication* app = new BApplication("application/x.vnd-Haiku.Scrolling");

        BRect frame(50.0, 50.0, 300.0, 250.0);
        show_window(frame, "Scrolling Test");

        app->Run();

        delete app;
        return 0;
}