* Implements View interface for a table, that is composed of an * element structure where the child elements of the element * this view is responsible for represent rows and the child * elements of the row elements are cells. The cell elements can * have an arbitrary element structure under them, which will * be built with the ViewFactory returned by the getViewFactory * method. *
* * TABLE * ROW * CELL * CELL * ROW * CELL * CELL * **
* This is implemented as a hierarchy of boxes, the table itself
* is a vertical box, the rows are horizontal boxes, and the cells
* are vertical boxes. The cells are allowed to span multiple
* columns and rows. By default, the table can be thought of as
* being formed over a grid (i.e. somewhat like one would find in
* gridbag layout), where table cells can request to span more
* than one grid cell. The default horizontal span of table cells
* will be based upon this grid, but can be changed by reimplementing
* the requested span of the cell (i.e. table cells can have independant
* spans if desired).
*
* @author Timothy Prinzing
* @see View
*/
public abstract class TableView extends BoxView {
/**
* Constructs a TableView for the given element.
*
* @param elem the element that this view is responsible for
*/
public TableView(Element elem) {
super(elem, View.Y_AXIS);
rows = new Vector
* This is implemented to call the
* layoutColumns method, and then
* forward to the superclass to actually carry out the layout
* of the tables rows.
*
* @param targetSpan the total span given to the view, which
* whould be used to layout the children.
* @param axis the axis being layed out.
* @param offsets the offsets from the origin of the view for
* each of the child views. This is a return value and is
* filled in by the implementation of this method.
* @param spans the span of each child view. This is a return
* value and is filled in by the implementation of this method.
*/
protected void layoutMinorAxis(int targetSpan, int axis, int[] offsets, int[] spans) {
// make grid is properly represented
updateGrid();
// all of the row layouts are invalid, so mark them that way
int n = getRowCount();
for (int i = 0; i < n; i++) {
TableRow row = getRow(i);
row.layoutChanged(axis);
}
// calculate column spans
layoutColumns(targetSpan, columnOffsets, columnSpans, columnRequirements);
// continue normal layout
super.layoutMinorAxis(targetSpan, axis, offsets, spans);
}
/**
* Calculate the requirements for the minor axis. This is called by
* the superclass whenever the requirements need to be updated (i.e.
* a preferenceChanged was messaged through this view).
*
* This is implemented to calculate the requirements as the sum of the
* requirements of the columns.
*/
protected SizeRequirements calculateMinorAxisRequirements(int axis, SizeRequirements r) {
updateGrid();
// calculate column requirements for each column
calculateColumnRequirements(axis);
// the requirements are the sum of the columns.
if (r == null) {
r = new SizeRequirements();
}
long min = 0;
long pref = 0;
long max = 0;
for (SizeRequirements req : columnRequirements) {
min += req.minimum;
pref += req.preferred;
max += req.maximum;
}
r.minimum = (int) min;
r.preferred = (int) pref;
r.maximum = (int) max;
r.alignment = 0;
return r;
}
/*
boolean shouldTrace() {
AttributeSet a = getElement().getAttributes();
Object o = a.getAttribute(HTML.Attribute.ID);
if ((o != null) && o.equals("debug")) {
return true;
}
return false;
}
*/
/**
* Calculate the requirements for each column. The calculation
* is done as two passes over the table. The table cells that
* occupy a single column are scanned first to determine the
* maximum of minimum, preferred, and maximum spans along the
* give axis. Table cells that span multiple columns are excluded
* from the first pass. A second pass is made to determine if
* the cells that span multiple columns are satisfied. If the
* column requirements are not satisified, the needs of the
* multi-column cell is mixed into the existing column requirements.
* The calculation of the multi-column distribution is based upon
* the proportions of the existing column requirements and taking
* into consideration any constraining maximums.
*/
void calculateColumnRequirements(int axis) {
// pass 1 - single column cells
boolean hasMultiColumn = false;
int nrows = getRowCount();
for (int i = 0; i < nrows; i++) {
TableRow row = getRow(i);
int col = 0;
int ncells = row.getViewCount();
for (int cell = 0; cell < ncells; cell++, col++) {
View cv = row.getView(cell);
for (; row.isFilled(col); col++); // advance to a free column
int rowSpan = getRowsOccupied(cv);
int colSpan = getColumnsOccupied(cv);
if (colSpan == 1) {
checkSingleColumnCell(axis, col, cv);
} else {
hasMultiColumn = true;
col += colSpan - 1;
}
}
}
// pass 2 - multi-column cells
if (hasMultiColumn) {
for (int i = 0; i < nrows; i++) {
TableRow row = getRow(i);
int col = 0;
int ncells = row.getViewCount();
for (int cell = 0; cell < ncells; cell++, col++) {
View cv = row.getView(cell);
for (; row.isFilled(col); col++); // advance to a free column
int colSpan = getColumnsOccupied(cv);
if (colSpan > 1) {
checkMultiColumnCell(axis, col, colSpan, cv);
col += colSpan - 1;
}
}
}
}
/*
if (shouldTrace()) {
System.err.println("calc:");
for (int i = 0; i < columnRequirements.length; i++) {
System.err.println(" " + i + ": " + columnRequirements[i]);
}
}
*/
}
/**
* check the requirements of a table cell that spans a single column.
*/
void checkSingleColumnCell(int axis, int col, View v) {
SizeRequirements req = columnRequirements[col];
req.minimum = Math.max((int) v.getMinimumSpan(axis), req.minimum);
req.preferred = Math.max((int) v.getPreferredSpan(axis), req.preferred);
req.maximum = Math.max((int) v.getMaximumSpan(axis), req.maximum);
}
/**
* check the requirements of a table cell that spans multiple
* columns.
*/
void checkMultiColumnCell(int axis, int col, int ncols, View v) {
// calculate the totals
long min = 0;
long pref = 0;
long max = 0;
for (int i = 0; i < ncols; i++) {
SizeRequirements req = columnRequirements[col + i];
min += req.minimum;
pref += req.preferred;
max += req.maximum;
}
// check if the minimum size needs adjustment.
int cmin = (int) v.getMinimumSpan(axis);
if (cmin > min) {
/*
* the columns that this cell spans need adjustment to fit
* this table cell.... calculate the adjustments. The
* maximum for each cell is the maximum of the existing
* maximum or the amount needed by the cell.
*/
SizeRequirements[] reqs = new SizeRequirements[ncols];
for (int i = 0; i < ncols; i++) {
SizeRequirements r = reqs[i] = columnRequirements[col + i];
r.maximum = Math.max(r.maximum, (int) v.getMaximumSpan(axis));
}
int[] spans = new int[ncols];
int[] offsets = new int[ncols];
SizeRequirements.calculateTiledPositions(cmin, null, reqs,
offsets, spans);
// apply the adjustments
for (int i = 0; i < ncols; i++) {
SizeRequirements req = reqs[i];
req.minimum = Math.max(spans[i], req.minimum);
req.preferred = Math.max(req.minimum, req.preferred);
req.maximum = Math.max(req.preferred, req.maximum);
}
}
// check if the preferred size needs adjustment.
int cpref = (int) v.getPreferredSpan(axis);
if (cpref > pref) {
/*
* the columns that this cell spans need adjustment to fit
* this table cell.... calculate the adjustments. The
* maximum for each cell is the maximum of the existing
* maximum or the amount needed by the cell.
*/
SizeRequirements[] reqs = new SizeRequirements[ncols];
for (int i = 0; i < ncols; i++) {
SizeRequirements r = reqs[i] = columnRequirements[col + i];
}
int[] spans = new int[ncols];
int[] offsets = new int[ncols];
SizeRequirements.calculateTiledPositions(cpref, null, reqs,
offsets, spans);
// apply the adjustments
for (int i = 0; i < ncols; i++) {
SizeRequirements req = reqs[i];
req.preferred = Math.max(spans[i], req.preferred);
req.maximum = Math.max(req.preferred, req.maximum);
}
}
}
/**
* Fetches the child view that represents the given position in
* the model. This is implemented to walk through the children
* looking for a range that contains the given position. In this
* view the children do not necessarily have a one to one mapping
* with the child elements.
*
* @param pos the search position >= 0
* @param a the allocation to the table on entry, and the
* allocation of the view containing the position on exit
* @return the view representing the given position, or
*
* This is re-implemented to give each child the span of the column
* width for the table, and to give cells that span multiple columns
* the multi-column span.
*
* @param targetSpan the total span given to the view, which
* whould be used to layout the children.
* @param axis the axis being layed out.
* @param offsets the offsets from the origin of the view for
* each of the child views. This is a return value and is
* filled in by the implementation of this method.
* @param spans the span of each child view. This is a return
* value and is filled in by the implementation of this method.
*/
protected void layoutMajorAxis(int targetSpan, int axis, int[] offsets, int[] spans) {
int col = 0;
int ncells = getViewCount();
for (int cell = 0; cell < ncells; cell++, col++) {
View cv = getView(cell);
for (; isFilled(col); col++); // advance to a free column
int colSpan = getColumnsOccupied(cv);
spans[cell] = columnSpans[col];
offsets[cell] = columnOffsets[col];
if (colSpan > 1) {
int n = columnSpans.length;
for (int j = 1; j < colSpan; j++) {
// Because the table may be only partially formed, some
// of the columns may not yet exist. Therefore we check
// the bounds.
if ((col+j) < n) {
spans[cell] += columnSpans[col+j];
}
}
col += colSpan - 1;
}
}
}
/**
* Perform layout for the minor axis of the box (i.e. the
* axis orthoginal to the axis that it represents). The results
* of the layout should be placed in the given arrays which represent
* the allocations to the children along the minor axis. This
* is called by the superclass whenever the layout needs to be
* updated along the minor axis.
*
* This is implemented to delegate to the superclass, then adjust
* the span for any cell that spans multiple rows.
*
* @param targetSpan the total span given to the view, which
* whould be used to layout the children.
* @param axis the axis being layed out.
* @param offsets the offsets from the origin of the view for
* each of the child views. This is a return value and is
* filled in by the implementation of this method.
* @param spans the span of each child view. This is a return
* value and is filled in by the implementation of this method.
*/
protected void layoutMinorAxis(int targetSpan, int axis, int[] offsets, int[] spans) {
super.layoutMinorAxis(targetSpan, axis, offsets, spans);
int col = 0;
int ncells = getViewCount();
for (int cell = 0; cell < ncells; cell++, col++) {
View cv = getView(cell);
for (; isFilled(col); col++); // advance to a free column
int colSpan = getColumnsOccupied(cv);
int rowSpan = getRowsOccupied(cv);
if (rowSpan > 1) {
for (int j = 1; j < rowSpan; j++) {
// test bounds of each row because it may not exist
// either because of error or because the table isn't
// fully loaded yet.
int row = getRow() + j;
if (row < TableView.this.getViewCount()) {
int span = TableView.this.getSpan(Y_AXIS, getRow()+j);
spans[cell] += span;
}
}
}
if (colSpan > 1) {
col += colSpan - 1;
}
}
}
/**
* Determines the resizability of the view along the
* given axis. A value of 0 or less is not resizable.
*
* @param axis may be either View.X_AXIS or View.Y_AXIS
* @return the resize weight
* @exception IllegalArgumentException for an invalid axis
*/
public int getResizeWeight(int axis) {
return 1;
}
/**
* Fetches the child view that represents the given position in
* the model. This is implemented to walk through the children
* looking for a range that contains the given position. In this
* view the children do not necessarily have a one to one mapping
* with the child elements.
*
* @param pos the search position >= 0
* @param a the allocation to the table on entry, and the
* allocation of the view containing the position on exit
* @return the view representing the given position, or
* null if there isn't one
*/
protected View getViewAtPosition(int pos, Rectangle a) {
int n = getViewCount();
for (int i = 0; i < n; i++) {
View v = getView(i);
int p0 = v.getStartOffset();
int p1 = v.getEndOffset();
if ((pos >= p0) && (pos < p1)) {
// it's in this view.
if (a != null) {
childAllocation(i, a);
}
return v;
}
}
if (pos == getEndOffset()) {
View v = getView(n - 1);
if (a != null) {
this.childAllocation(n - 1, a);
}
return v;
}
return null;
}
// ---- variables ----------------------------------------------------
int[] columnSpans;
int[] columnOffsets;
SizeRequirements[] columnRequirements;
Vectornull if there isn't one
*/
protected View getViewAtPosition(int pos, Rectangle a) {
int n = getViewCount();
for (int i = 0; i < n; i++) {
View v = getView(i);
int p0 = v.getStartOffset();
int p1 = v.getEndOffset();
if ((pos >= p0) && (pos < p1)) {
// it's in this view.
if (a != null) {
childAllocation(i, a);
}
return v;
}
}
if (pos == getEndOffset()) {
View v = getView(n - 1);
if (a != null) {
this.childAllocation(n - 1, a);
}
return v;
}
return null;
}
/** columns filled by multi-column or multi-row cells */
BitSet fillColumns;
/** the row within the overall grid */
int row;
}
/**
* @deprecated A table cell can now be any View implementation.
*/
@Deprecated
public class TableCell extends BoxView implements GridCell {
/**
* Constructs a TableCell for the given element.
*
* @param elem the element that this view is responsible for
* @since 1.4
*/
public TableCell(Element elem) {
super(elem, View.Y_AXIS);
}
// --- GridCell methods -------------------------------------
/**
* Gets the number of columns this cell spans (e.g. the
* grid width).
*
* @return the number of columns
*/
public int getColumnCount() {
return 1;
}
/**
* Gets the number of rows this cell spans (that is, the
* grid height).
*
* @return the number of rows
*/
public int getRowCount() {
return 1;
}
/**
* Sets the grid location.
*
* @param row the row >= 0
* @param col the column >= 0
*/
public void setGridLocation(int row, int col) {
this.row = row;
this.col = col;
}
/**
* Gets the row of the grid location
*/
public int getGridRow() {
return row;
}
/**
* Gets the column of the grid location
*/
public int getGridColumn() {
return col;
}
int row;
int col;
}
/**
*
* THIS IS NO LONGER USED, AND WILL BE REMOVED IN THE
* NEXT RELEASE. THE JCK SIGNATURE TEST THINKS THIS INTERFACE
* SHOULD EXIST
*
*/
interface GridCell {
/**
* Sets the grid location.
*
* @param row the row >= 0
* @param col the column >= 0
*/
public void setGridLocation(int row, int col);
/**
* Gets the row of the grid location
*/
public int getGridRow();
/**
* Gets the column of the grid location
*/
public int getGridColumn();
/**
* Gets the number of columns this cell spans (e.g. the
* grid width).
*
* @return the number of columns
*/
public int getColumnCount();
/**
* Gets the number of rows this cell spans (that is, the
* grid height).
*
* @return the number of rows
*/
public int getRowCount();
}
}