MacTech 1 to 12/MacTech-vol-1-12.toast/Source/MacTech® Magazine/Volume 07 - 1991/07.08 Aug 91/Dots Source/cDotsTask.c

C/C++ Source or Header | 1989-11-02 | 4.6 KB | 202 lines | [TEXT/KAHL]

/***************************************
    cDotsTask.c

    SUPERCLASS = CMouseTask

Handles mouse clicks in the dots pane.
Also provides undo/redo capability.

****************************************/

#include "cDotsTask.h"
#include "dotsTypes.h"

/******** C O N S T R U C T I O N ********/

/*** IDotsTask
*
* Initialize a DotsTask object
*/
void    cDotsTask::IDotsTask(
    short        aNameIndex,
    cDotsPane    *theDotsPane,
    cDotsDoc    *theDotsDoc)
{
    inherited::IMouseTask(aNameIndex);

        /* Initialize instance variables */
    fDotsPane = theDotsPane;
    fDotsDoc = theDotsDoc;
    fPlayerMoved = fDotsDoc->getPlayerTurn();    /* Player whose move it is */
    fValidMove = false;    /* Only valid if a previously unselected
                        ** line is selected by this mouse task */
    fDirection = hLine;
    fRow = -1;
    fCol = -1;
}

/*****  M O U S E   T R A C K I N G ********/

/*** BeginTracking {OVERRIDE}
*
* Mouse tracking starting. Adjust starting pt.
*/
void    cDotsTask::BeginTracking(
    Point        *startPt)
{

    tLineDir    direction;
    int            row;
    int            col;
    Rect        r;

        /* See if pt is on a line */
    if (fDotsPane->pt2Line(*startPt, &direction, &row, &col)) {
            /* Convert line coords to a pt on the grid */
        fDotsPane->line2Pt(direction, row, col, startPt);
            /* If line unoccupied then fill it */
        if (!fDotsDoc->getLineState(direction, row, col)) {
            fDotsPane->line2Rect(direction, row, col, &r);
            FillRect(&r, black);
        }
    }
}


/*** KeepTracking {OVERRIDE}
*
* Continuous mouse tracking while the mouse button is down. Draw
* only when the mouse moves or the panorama autoscrolls.
*/
void    cDotsTask::KeepTracking(
    Point        *currPt,
    Point        *prevPt,
    Point        *startPt)
{

    int            col;
    tLineDir    direction;
    Boolean        eraseIt;
    Rect        r;
    int            row;

        /* Only track if not autoScrolling */
    if (!fDotsPane->AutoScroll(*currPt)) {

            /* assume won't erase line previously chosen
            ** by this mouse down */
        eraseIt = false;

            /* Check for current pt on a line */
        if (fDotsPane->pt2Line(*currPt, &direction, &row, &col)) {
                /* Convert line coords to a pt on the grid */
            fDotsPane->line2Pt(direction, row, col, currPt);
                /* Check for new chosen line */
             if (!EqualPt(*currPt, *startPt)) {
                    /* If new chosen line unoccupied then fill it */
                if (!fDotsDoc->getLineState(direction, row, col)) {
                    fDotsPane->line2Rect(direction, row, col, &r);
                    FillRect(&r, black);
                }
                eraseIt = true;    /* erase previous line */
            }
        } else
            eraseIt = true;    /* Erase any previously chosen line */

            /* If no longer over a previously chosen line then erase it */
        if (eraseIt) {
                /* Check if start pt on a line */
            if (fDotsPane->pt2Line(*startPt, &direction, &row, &col)) {
                    /* Only erase if start line is unoccupied */
                if (!fDotsDoc->getLineState(direction, row, col)) {
                        /* erase the previouly chosen line */
                    fDotsPane->line2Rect(direction, row, col, &r);
                    FillRect(&r, white);
                        /* redraw both dots */
                    fDotsPane->dot2Rect(row, col, &r);
                    FillOval(&r, black);
                    if (direction == hLine)
                        col++;
                    else
                        row++;
                    fDotsPane->dot2Rect(row, col, &r);
                    FillOval(&r, black);
                }
            }
                /* Reset startPt to new point */
            SetPt(startPt, currPt->h, currPt->v);
        }
    }
}


/*** EndTracking {OVERRIDE}
*
* Mouse down tracking has ended because the user has released the
* mouse button. Its now time to complete the move and set up the undo.
*/
void    cDotsTask::EndTracking(
    Point        *currPt,
    Point        *prevPt,
    Point        *startPt)
{
    tLineDir    direction;
    int            row;
    int            col;

        /* The only valid move is the selection of a previously
        ** unselected line so check if selected point is on line
        ** and the line is unoccupied */
    if ((fDotsPane->pt2Line(*prevPt, &direction, &row, &col)) &&
        (!fDotsDoc->getLineState(direction, row, col))) {
        fValidMove = true;
        fDirection = direction;
        fRow = row;
        fCol = col;

        Do();    /* Act on users choice */
    }
}

/*********** D O   /   U N D O ***********/

/*** Do  {OVERRIDE}
*
* Perform a dots pane task, user chose a line
*/
void    cDotsTask::Do()
{
    fDotsDoc->setLineState(fDirection, fRow, fCol, fPlayerMoved, true);
}

/*** Undo {OVERRIDE}
*
* Undo an action performed by a dots pane task
*/
void    cDotsTask::Undo()
{
    fDotsDoc->setLineState(fDirection, fRow, fCol, fPlayerMoved, false);
}

/*** Redo {OVERRIDE}
*
* Redo an action performed by a dots pane task
*/
void    cDotsTask::Redo()
{
    fDotsDoc->setLineState(fDirection, fRow, fCol, fPlayerMoved, true);
}

/*********** A C C E S S ***********/

/*** validMove
*
* Return value of fValidMove instance variable.
* The value will be true if a previously unselected line was selected
* during this mouse task, false otherwise.
*/
Boolean    cDotsTask::validMove()
{
    return(fValidMove);
}