source: Main/DrafterLib/context.cpp @ 8

/*
 * Copyright 2011 Dewey Taylor (james.dewey.taylor@gmail.com)
 * All rights reserved. Distributed under the terms of the MIT license.
 */

#include "Drafter.h"
#include "DrafterPrivateDefs.h"

#include <iostream>

// TODO: add parameters like width, height, team id, workspace, etc
uint32
CreateContext()
{
#ifdef __HAIKU__
        // set sizes etc
        uint32 size = sizeof(ContextData) * DRAFTER_MAX_CONTEXTS + sizeof(uint32);
        if (size > B_PAGE_SIZE)
        {
                //panic("Drafter context area size larger than page size\n");
cout<<"Context area size larger than page size"<<endl;
                return D_ERR_NO_CONTEXT_AVAILABLE;
        }

        // check if we already know about an existing area
        if (context_area == B_ERROR)
        {
                char* temp_addr = NULL;
                // check if an area already exists
                area_id temp_area = find_area(CONTEXT_AREA_NAME);
                // if not, create one, then clone it
                if (temp_area == B_NAME_NOT_FOUND)
                {
                        // create a new area
                        temp_area = create_area(CONTEXT_AREA_NAME, &(void*)temp_addr, B_ANY_ADDRESS, B_PAGE_SIZE, B_CONTIGUOUS, B_READ_AREA | B_WRITE_AREA);
cout<<"Creating Area: "<<temp_area<<endl;
                }
                // clone the area
                context_area = clone_area(CONTEXT_AREA_CLONE_NAME, &(void*)context_addr, B_ANY_ADDRESS, B_READ_AREA | B_WRITE_AREA, temp_area);
                // increment usage counter
                if (context_area < B_OK)
                {
cout<<"Cannot clone area"<<endl;
                        return D_ERR_NO_CONTEXT_AVAILABLE;
                }
                contexts = (ContextData*)context_addr;
                contextCount = (uint32*)context_addr + sizeof(ContextData) * DRAFTER_MAX_CONTEXTS;
                *contextCount++;
        }
#endif
        // TODO: add locking
        bool foundcontext = false;
        int a;
        for (a = 0; a < DRAFTER_MAX_CONTEXTS; a++)
        {
                if ((contexts[a].flags & DRAFTER_CONTEXT_USED) == 0)
                {
                        // use this context!
                        contexts[a].flags |= DRAFTER_CONTEXT_USED;
                        foundcontext = true;
                        break;
                }
        }
        if (foundcontext == false)
        {
                a = D_ERR_NO_CONTEXT_AVAILABLE;
        }
        return a;
}

uint32
SwitchContext(uint32 context)
{
        if (context < DRAFTER_MAX_CONTEXTS)
        {
                if (contexts[context].flags & DRAFTER_CONTEXT_USED)
                {
                        // how do we specify the current context? local variable in the app?
                        current_context = context;
                }
        }
        return D_ERR_BAD_CONTEXT_ID;
}

uint32
DeleteContext(uint32 context)
{
// TODO: add locking
// TODO: check the teamID too
        if (context < DRAFTER_MAX_CONTEXTS)
        {
                if (contexts[context].flags & DRAFTER_CONTEXT_USED)
                {
                        contexts[context].flags &= 0xFFFFFFFF - DRAFTER_CONTEXT_USED;
                        return D_OK;
                }
        }
        return D_ERR_BAD_CONTEXT_ID;
}