/**
* Adjusts the given row if possible to fit within the layout span. By default this will try to
* find the highest break weight possible nearest the end of the row. If a forced break is
* encountered, the break will be positioned there.
*
* @param rowIndex the row to adjust to the current layout span.
* @param desiredSpan the current layout span >= 0
* @param x the location r starts at.
*/
protected void adjustRow(FlowView fv, int rowIndex, int desiredSpan, int x) {
final int flowAxis = fv.getFlowAxis();
View r = fv.getView(rowIndex);
int n = r.getViewCount();
int span = 0;
int bestWeight = BadBreakWeight;
int bestSpan = 0;
int bestIndex = -1;
int bestOffset = 0;
View v;
for (int i = 0; i < n; i++) {
v = r.getView(i);
int spanLeft = desiredSpan - span;
int w = v.getBreakWeight(flowAxis, x + span, spanLeft);
if ((w >= bestWeight) && (w > BadBreakWeight)) {
bestWeight = w;
bestIndex = i;
bestSpan = span;
if (w >= ForcedBreakWeight) {
// it's a forced break, so there is
// no point in searching further.
break;
}
}
span += v.getPreferredSpan(flowAxis);
}
if (bestIndex < 0) {
// there is nothing that can be broken, leave
// it in it's current state.
return;
}
// Break the best candidate view, and patch up the row.
int spanLeft = desiredSpan - bestSpan;
v = r.getView(bestIndex);
v = v.breakView(flowAxis, v.getStartOffset(), x + bestSpan, spanLeft);
View[] va = new View[1];
va[0] = v;
View lv = getLogicalView(fv);
for (int i = bestIndex; i < n; i++) {
View tmpView = r.getView(i);
if (contains(lv, tmpView)) {
tmpView.setParent(lv);
} else if (tmpView.getViewCount() > 0) {
recursiveReparent(tmpView, lv);
}
}
r.replace(bestIndex, n - bestIndex, va);
}
/**
* Determines the preferred span for this view along an axis.
*
* @param axis may be either View.X_AXIS or View.Y_AXIS
* @return the span the view would like to be rendered into. Typically the view is told to
* render into the span that is returned, although there is no guarantee. The parent may
* choose to resize or break the view.
* @see View#getPreferredSpan
*/
public float getPreferredSpan(int axis) {
float maxpref = 0;
float pref = 0;
int n = getViewCount();
for (int i = 0; i < n; i++) {
View v = getView(i);
pref += v.getPreferredSpan(axis);
if (v.getBreakWeight(axis, 0, Short.MAX_VALUE) >= ForcedBreakWeight) {
maxpref = Math.max(maxpref, pref);
pref = 0;
}
}
maxpref = Math.max(maxpref, pref);
return maxpref;
}
/**
* Determines the minimum span for this view along an axis. The is implemented to find the
* minimum unbreakable span.
*
* @param axis may be either View.X_AXIS or View.Y_AXIS
* @return the span the view would like to be rendered into. Typically the view is told to
* render into the span that is returned, although there is no guarantee. The parent may
* choose to resize or break the view.
* @see View#getPreferredSpan
*/
public float getMinimumSpan(int axis) {
float maxmin = 0;
float min = 0;
boolean nowrap = false;
int n = getViewCount();
for (int i = 0; i < n; i++) {
View v = getView(i);
if (v.getBreakWeight(axis, 0, Short.MAX_VALUE) == BadBreakWeight) {
min += v.getPreferredSpan(axis);
nowrap = true;
} else if (nowrap) {
maxmin = Math.max(min, maxmin);
nowrap = false;
min = 0;
}
}
maxmin = Math.max(maxmin, min);
return maxmin;
}
/**
* Creates a row of views that will fit within the layout span of the row. This is called by the
* layout method. This is implemented to fill the row by repeatedly calling the createView
* method until the available span has been exhausted, a forced break was encountered, or the
* createView method returned null. If the remaining span was exhaused, the adjustRow method
* will be called to perform adjustments to the row to try and make it fit into the given span.
*
* @param rowIndex the index of the row to fill in with views. The row is assumed to be empty on
* entry.
* @param pos The current position in the children of this views element from which to start.
* @return the position to start the next row
*/
protected int layoutRow(FlowView fv, int rowIndex, int pos) {
View row = fv.getView(rowIndex);
int x = fv.getFlowStart(rowIndex);
int spanLeft = fv.getFlowSpan(rowIndex);
int end = fv.getEndOffset();
TabExpander te = (fv instanceof TabExpander) ? (TabExpander) fv : null;
// Indentation.
int preX = x;
int availableSpan = spanLeft;
preX = x;
final int flowAxis = fv.getFlowAxis();
boolean forcedBreak = false;
while (pos < end && spanLeft > 0) {
View v = createView(fv, pos, spanLeft, rowIndex);
if (v == null) {
break;
}
int chunkSpan;
if ((flowAxis == X_AXIS) && (v instanceof TabableView)) {
chunkSpan = (int) ((TabableView) v).getTabbedSpan(x, te);
} else {
chunkSpan = (int) v.getPreferredSpan(flowAxis);
}
// If a forced break is necessary, break
if (v.getBreakWeight(flowAxis, pos, spanLeft) >= ForcedBreakWeight) {
int n = row.getViewCount();
if (n > 0) {
/* If this is a forced break and it's not the only view
* the view should be replaced with a call to breakView.
* If it's it only view, it should be used directly. In
* either case no more children should be added beyond this
* view.
*/
v = v.breakView(flowAxis, pos, x, spanLeft);
if (v != null) {
if ((flowAxis == X_AXIS) && (v instanceof TabableView)) {
chunkSpan = (int) ((TabableView) v).getTabbedSpan(x, te);
} else {
chunkSpan = (int) v.getPreferredSpan(flowAxis);
}
} else {
chunkSpan = 0;
}
}
forcedBreak = true;
}
spanLeft -= chunkSpan;
x += chunkSpan;
if (v != null) {
row.append(v);
pos = v.getEndOffset();
}
if (forcedBreak) {
break;
}
}
if (spanLeft < 0) {
// This row is too long and needs to be adjusted.
adjustRow(fv, rowIndex, availableSpan, preX);
} else if (row.getViewCount() == 0) {
// Impossible spec... put in whatever is left.
View v = createView(fv, pos, Integer.MAX_VALUE, rowIndex);
row.append(v);
}
return row.getEndOffset();
}