view release on metacpan or  search on metacpan

pTk/mTk/generic/tkGrid.c  view on Meta::CPAN

		    UniformGroup *new = (UniformGroup *) ckalloc(newSize);
		    UniformGroup *old = uniformGroupPtr;
		    memcpy((VOID *) new, (VOID *) old, oldSize);
		    if (old != uniformPre) {
			ckfree((char *) old);
		    }
		    uniformGroupPtr = new;
		    uniformGroupsAlloced += UNIFORM_PREALLOC;
		}
		uniformGroups++;
		uniformGroupPtr[start].group = layoutPtr[slot].uniform;
		uniformGroupPtr[start].minSize = 0;
	    }
	    weight = layoutPtr[slot].weight;
	    weight = weight > 0 ? weight : 1;
	    minSize = (layoutPtr[slot].minSize + weight - 1) / weight;
	    if (minSize > uniformGroupPtr[start].minSize) {
		uniformGroupPtr[start].minSize = minSize;
	    }
	}
    }

    /*
     * Data has been gathered about uniform groups. Now relayout accordingly.
     */

    if (uniformGroups > 0) {
	for (slot = 0; slot < gridCount; slot++) {
	    if (layoutPtr[slot].uniform != NULL) {
		for (start = 0; start < uniformGroups; start++) {
		    if (uniformGroupPtr[start].group ==
			    layoutPtr[slot].uniform) {
			weight = layoutPtr[slot].weight;
			weight = weight > 0 ? weight : 1;
			layoutPtr[slot].minSize =
				uniformGroupPtr[start].minSize * weight;
			break;
		    }
		}
	    }
	}
    }

    if (uniformGroupPtr != uniformPre) {
	ckfree((char *) uniformGroupPtr);
    }

    /*
     * Step 3.
     * Determine the minimum slot offsets going from left to right
     * that would fit all of the slaves.  This determines the minimum
     */

    for (offset=slot=0; slot < gridCount; slot++) {
        layoutPtr[slot].minOffset = layoutPtr[slot].minSize + offset;
        for (slavePtr = layoutPtr[slot].binNextPtr; slavePtr != NULL;
                    slavePtr = slavePtr->binNextPtr) {
	    int span = (slotType == COLUMN) ? slavePtr->numCols : slavePtr->numRows;
            int required = slavePtr->size + layoutPtr[slot - span].minOffset;
            if (required > layoutPtr[slot].minOffset) {
                layoutPtr[slot].minOffset = required;
            }
        }
        offset = layoutPtr[slot].minOffset;
    }

    /*
     * At this point, we know the minimum required size of the entire layout.
     * It might be prudent to stop here if our "master" will resize itself
     * to this size.
     */

    requiredSize = offset;
    if (maxOffset > offset) {
    	offset=maxOffset;
    }

    /*
     * Step 4.
     * Determine the minimum slot offsets going from right to left,
     * bounding the pixel range of each slot boundary.
     * Pre-fill all of the right offsets with the actual size of the table;
     * they will be reduced as required.
     */

    for (slot=0; slot < gridCount; slot++) {
        layoutPtr[slot].maxOffset = offset;
    }
    for (slot=gridCount-1; slot > 0;) {
        for (slavePtr = layoutPtr[slot].binNextPtr; slavePtr != NULL;
                    slavePtr = slavePtr->binNextPtr) {
	    int span = (slotType == COLUMN) ? slavePtr->numCols : slavePtr->numRows;
            int require = offset - slavePtr->size;
            int startSlot  = slot - span;
            if (startSlot >=0 && require < layoutPtr[startSlot].maxOffset) {
                layoutPtr[startSlot].maxOffset = require;
            }
	}
	offset -= layoutPtr[slot].minSize;
	slot--;
	if (layoutPtr[slot].maxOffset < offset) {
	    offset = layoutPtr[slot].maxOffset;
	} else {
	    layoutPtr[slot].maxOffset = offset;
	}
    }

    /*
     * Step 5.
     * At this point, each slot boundary has a range of values that
     * will satisfy the overall layout size.
     * Make repeated passes over the layout structure looking for
     * spans of slot boundaries where the minOffsets are less than
     * the maxOffsets, and adjust the offsets according to the slot
     * weights.  At each pass, at least one slot boundary will have
     * its range of possible values fixed at a single value.
     */

    for (start=0; start < gridCount;) {
    	int totalWeight = 0;	/* Sum of the weights for all of the
    				 * slots in this span. */
    	int need = 0;		/* The minimum space needed to layout
    				 * this span. */
    	int have;		/* The actual amount of space that will
    				 * be taken up by this span. */
    	int weight;		/* Cumulative weights of the columns in
    				 * this span. */
    	int noWeights = 0;	/* True if the span has no weights. */

    	/*
    	 * Find a span by identifying ranges of slots whose edges are
    	 * already constrained at fixed offsets, but whose internal
    	 * slot boundaries have a range of possible positions.
    	 */

    	if (layoutPtr[start].minOffset == layoutPtr[start].maxOffset) {
	    start++;
	    continue;
	}

	for (end=start+1; end<gridCount; end++) {
	    if (layoutPtr[end].minOffset == layoutPtr[end].maxOffset) {
		break;
	    }
	}

	/*
	 * We found a span.  Compute the total weight, minumum space required,
	 * for this span, and the actual amount of space the span should
	 * use.
	 */

	for (slot=start; slot<=end; slot++) {
	    totalWeight += layoutPtr[slot].weight;
	    need += layoutPtr[slot].minSize;
	}