/** Adds a match to align the left edge with some other edge. */
private void addLeftSideMatch(int x1, List<GridMatch> columnMatches, int max) {
int column = (mGrid.getViewCount() == 0) ? 0 : mGrid.getClosestColumn(x1);
int columnX = mGrid.getColumnX(column);
int distance = abs(columnX - x1);
if (distance <= max) {
columnMatches.add(
new GridMatch(SegmentType.LEFT, distance, columnX, column, false, UNDEFINED));
}
}
/** Adds a match to align the bottom edge with some other edge. */
private void addBottomMatch(int y2, List<GridMatch> rowMatches, int max) {
int rowBottom = (mGrid.getViewCount() == 0) ? 0 : mGrid.getClosestRow(y2);
int distance = mGrid.getRowDistance(rowBottom, y2);
if (distance < max) {
int rowY = mGrid.getRowY(rowBottom);
if (rowY > mGrid.layout.getBounds().y) {
rowMatches.add(
new GridMatch(SegmentType.BOTTOM, distance, rowY, rowBottom, false, UNDEFINED));
}
}
}
/** Adds a match to align the right edge with some other edge. */
private void addRightSideMatch(int x2, List<GridMatch> columnMatches, int max) {
// TODO: Only match the right hand side if the drag bounds fit fully within the
// cell! Ditto for match below.
int columnRight = (mGrid.getViewCount() == 0) ? 0 : mGrid.getClosestColumn(x2);
int rightDistance = mGrid.getColumnDistance(columnRight, x2);
if (rightDistance < max) {
int columnX = mGrid.getColumnX(columnRight);
if (columnX > mGrid.layout.getBounds().x) {
columnMatches.add(
new GridMatch(
SegmentType.RIGHT, rightDistance, columnX, columnRight, false, UNDEFINED));
}
}
}
/**
* Computes the best horizontal and vertical matches for a drag to the given position.
*
* @param feedback a {@link DropFeedback} object containing drag state like the drag bounds and
* the drag baseline
* @param p the mouse position
*/
public void computeMatches(DropFeedback feedback, Point p) {
mRowMatch = mColumnMatch = null;
feedback.tooltip = null;
Rect bounds = mGrid.layout.getBounds();
int x1 = p.x;
int y1 = p.y;
Rect dragBounds = feedback.dragBounds;
int w = dragBounds != null ? dragBounds.w : 0;
int h = dragBounds != null ? dragBounds.h : 0;
if (!GridLayoutRule.sGridMode) {
if (dragBounds != null) {
// Sometimes the items are centered under the mouse so
// offset by the top left corner distance
x1 += dragBounds.x;
y1 += dragBounds.y;
}
int x2 = x1 + w;
int y2 = y1 + h;
if (x2 < bounds.x || y2 < bounds.y || x1 > bounds.x2() || y1 > bounds.y2()) {
return;
}
List<GridMatch> columnMatches = new ArrayList<GridMatch>();
List<GridMatch> rowMatches = new ArrayList<GridMatch>();
int max = BaseLayoutRule.getMaxMatchDistance();
// Column matches:
addLeftSideMatch(x1, columnMatches, max);
addRightSideMatch(x2, columnMatches, max);
addCenterColumnMatch(bounds, x1, y1, x2, y2, columnMatches, max);
// Row matches:
int row = (mGrid.getViewCount() == 0) ? 0 : mGrid.getClosestRow(y1);
int rowY = mGrid.getRowY(row);
addTopMatch(y1, rowMatches, max, row, rowY);
addBaselineMatch(feedback.dragBaseline, y1, rowMatches, max, row, rowY);
addBottomMatch(y2, rowMatches, max);
// Look for gap-matches: Predefined spacing between widgets.
// TODO: Make this use metadata for predefined spacing between
// pairs of types of components. For example, buttons have certain
// inserts in their 9-patch files (depending on the theme) that should
// be considered and subtracted from the overall proposed distance!
addColumnGapMatch(bounds, x1, x2, columnMatches, max);
addRowGapMatch(bounds, y1, y2, rowMatches, max);
// Fallback: Split existing cell. Also do snap-to-grid.
if (GridLayoutRule.sSnapToGrid) {
x1 = ((x1 - MARGIN_SIZE - bounds.x) / GRID_SIZE) * GRID_SIZE + MARGIN_SIZE + bounds.x;
y1 = ((y1 - MARGIN_SIZE - bounds.y) / GRID_SIZE) * GRID_SIZE + MARGIN_SIZE + bounds.y;
x2 = x1 + w;
y2 = y1 + h;
}
if (columnMatches.size() == 0 && x1 >= bounds.x) {
// Split the current cell since we have no matches
// TODO: Decide whether it should be gravity left or right...
columnMatches.add(
new GridMatch(
SegmentType.LEFT, 0, x1, mGrid.getColumn(x1), true /* createCell */, UNDEFINED));
}
if (rowMatches.size() == 0 && y1 >= bounds.y) {
rowMatches.add(
new GridMatch(
SegmentType.TOP, 0, y1, mGrid.getRow(y1), true /* createCell */, UNDEFINED));
}
// Pick best matches
Collections.sort(rowMatches);
Collections.sort(columnMatches);
mColumnMatch = null;
mRowMatch = null;
String columnDescription = null;
String rowDescription = null;
if (columnMatches.size() > 0) {
mColumnMatch = columnMatches.get(0);
columnDescription = mColumnMatch.getDisplayName(mGrid.layout);
}
if (rowMatches.size() > 0) {
mRowMatch = rowMatches.get(0);
rowDescription = mRowMatch.getDisplayName(mGrid.layout);
}
if (columnDescription != null && rowDescription != null) {
feedback.tooltip = columnDescription + '\n' + rowDescription;
}
feedback.invalidTarget = mColumnMatch == null || mRowMatch == null;
} else {
// Find which cell we're inside.
// TODO: Find out where within the cell we are, and offer to tweak the gravity
// based on the position.
int column = mGrid.getColumn(x1);
int row = mGrid.getRow(y1);
int leftDistance = mGrid.getColumnDistance(column, x1);
int rightDistance = mGrid.getColumnDistance(column + 1, x1);
int topDistance = mGrid.getRowDistance(row, y1);
int bottomDistance = mGrid.getRowDistance(row + 1, y1);
int SLOP = 2;
int radius = mRule.getNewCellSize();
if (rightDistance < radius + SLOP) {
column = Math.min(column + 1, mGrid.actualColumnCount);
leftDistance = rightDistance;
}
if (bottomDistance < radius + SLOP) {
row = Math.min(row + 1, mGrid.actualRowCount);
topDistance = bottomDistance;
}
boolean createColumn = leftDistance < radius + SLOP;
boolean createRow = topDistance < radius + SLOP;
if (x1 >= bounds.x2()) {
createColumn = true;
}
if (y1 >= bounds.y2()) {
createRow = true;
}
int cellWidth = leftDistance + rightDistance;
int cellHeight = topDistance + bottomDistance;
SegmentType horizontalType = SegmentType.LEFT;
SegmentType verticalType = SegmentType.TOP;
int minDistance = 10; // Don't center or right/bottom align in tiny cells
if (!createColumn
&& leftDistance > minDistance
&& dragBounds != null
&& dragBounds.w < cellWidth - 10) {
if (rightDistance < leftDistance) {
horizontalType = SegmentType.RIGHT;
}
int centerDistance = Math.abs(cellWidth / 2 - leftDistance);
if (centerDistance < leftDistance / 2 && centerDistance < rightDistance / 2) {
horizontalType = SegmentType.CENTER_HORIZONTAL;
}
}
if (!createRow
&& topDistance > minDistance
&& dragBounds != null
&& dragBounds.h < cellHeight - 10) {
if (bottomDistance < topDistance) {
verticalType = SegmentType.BOTTOM;
}
int centerDistance = Math.abs(cellHeight / 2 - topDistance);
if (centerDistance < topDistance / 2 && centerDistance < bottomDistance / 2) {
verticalType = SegmentType.CENTER_VERTICAL;
}
}
mColumnMatch = new GridMatch(horizontalType, 0, x1, column, createColumn, 0);
mRowMatch = new GridMatch(verticalType, 0, y1, row, createRow, 0);
StringBuilder description = new StringBuilder(50);
String rowString = Integer.toString(mColumnMatch.cellIndex + 1);
String columnString = Integer.toString(mRowMatch.cellIndex + 1);
if (mRowMatch.createCell && mRowMatch.cellIndex < mGrid.actualRowCount) {
description.append(String.format("Shift row %1$d down", mRowMatch.cellIndex + 1));
description.append('\n');
}
if (mColumnMatch.createCell && mColumnMatch.cellIndex < mGrid.actualColumnCount) {
description.append(String.format("Shift column %1$d right", mColumnMatch.cellIndex + 1));
description.append('\n');
}
description.append(String.format("Insert into cell (%1$s,%2$s)", rowString, columnString));
description.append('\n');
description.append(
String.format(
"Align %1$s, %2$s",
horizontalType.name().toLowerCase(Locale.US),
verticalType.name().toLowerCase(Locale.US)));
feedback.tooltip = description.toString();
}
}