/** * Computes a horizontal "gap" match - a preferred distance from the nearest edge, including * margin edges */ private void addColumnGapMatch( Rect bounds, int x1, int x2, List<GridMatch> columnMatches, int max) { if (x1 < bounds.x + MARGIN_SIZE + max) { int matchedLine = bounds.x + MARGIN_SIZE; int distance = abs(matchedLine - x1); if (distance <= max) { boolean createCell = mGrid.getColumnX(mGrid.getColumn(matchedLine)) != matchedLine; columnMatches.add( new GridMatch(SegmentType.LEFT, distance, matchedLine, 0, createCell, MARGIN_SIZE)); } } else if (x2 > bounds.x2() - MARGIN_SIZE - max) { int matchedLine = bounds.x2() - MARGIN_SIZE; int distance = abs(matchedLine - x2); if (distance <= max) { // This does not yet work properly; we need to use columnWeights to achieve this // boolean createCell = mGrid.getColumnX(mGrid.getColumn(matchedLine)) != matchedLine; // columnMatches.add(new GridMatch(SegmentType.RIGHT, distance, matchedLine, // mGrid.actualColumnCount - 1, createCell, MARGIN_SIZE)); } } else { int columnRight = mGrid.getColumn(x1 - SHORT_GAP_DP); int columnX = mGrid.getColumnMaxX(columnRight); int matchedLine = columnX + SHORT_GAP_DP; int distance = abs(matchedLine - x1); if (distance <= max) { boolean createCell = mGrid.getColumnX(mGrid.getColumn(matchedLine)) != matchedLine; columnMatches.add( new GridMatch( SegmentType.LEFT, distance, matchedLine, columnRight, createCell, SHORT_GAP_DP)); } // Add a column directly adjacent (no gap) columnRight = mGrid.getColumn(x1); columnX = mGrid.getColumnMaxX(columnRight); matchedLine = columnX; distance = abs(matchedLine - x1); // Let's say you have this arrangement: // [button1][button2] // This is two columns, where the right hand side edge of column 1 is // flush with the left side edge of column 2, because in fact the width of // button1 is what defines the width of column 1, and that in turn is what // defines the left side position of column 2. // // In this case we don't want to consider inserting a new column at the // right hand side of button1 a better match than matching left on column 2. // Therefore, to ensure that this doesn't happen, we "penalize" right column // matches such that they don't get preferential treatment when the matching // line is on the left side of the column. distance += 2; if (distance <= max) { boolean createCell = mGrid.getColumnX(mGrid.getColumn(matchedLine)) != matchedLine; columnMatches.add( new GridMatch(SegmentType.LEFT, distance, matchedLine, columnRight, createCell, 0)); } } }
/** 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 a vertical "gap" match - a preferred distance from the nearest edge, including margin * edges */ private void addRowGapMatch(Rect bounds, int y1, int y2, List<GridMatch> rowMatches, int max) { if (y1 < bounds.y + MARGIN_SIZE + max) { int matchedLine = bounds.y + MARGIN_SIZE; int distance = abs(matchedLine - y1); if (distance <= max) { boolean createCell = mGrid.getRowY(mGrid.getRow(matchedLine)) != matchedLine; rowMatches.add( new GridMatch(SegmentType.TOP, distance, matchedLine, 0, createCell, MARGIN_SIZE)); } } else if (y2 > bounds.y2() - MARGIN_SIZE - max) { int matchedLine = bounds.y2() - MARGIN_SIZE; int distance = abs(matchedLine - y2); if (distance <= max) { // This does not yet work properly; we need to use columnWeights to achieve this // boolean createCell = mGrid.getRowY(mGrid.getRow(matchedLine)) != matchedLine; // rowMatches.add(new GridMatch(SegmentType.BOTTOM, distance, matchedLine, // mGrid.actualRowCount - 1, createCell, MARGIN_SIZE)); } } else { int rowBottom = mGrid.getRow(y1 - SHORT_GAP_DP); int rowY = mGrid.getRowMaxY(rowBottom); int matchedLine = rowY + SHORT_GAP_DP; int distance = abs(matchedLine - y1); if (distance <= max) { boolean createCell = mGrid.getRowY(mGrid.getRow(matchedLine)) != matchedLine; rowMatches.add( new GridMatch( SegmentType.TOP, distance, matchedLine, rowBottom, createCell, SHORT_GAP_DP)); } // Add a row directly adjacent (no gap) rowBottom = mGrid.getRow(y1); rowY = mGrid.getRowMaxY(rowBottom); matchedLine = rowY; distance = abs(matchedLine - y1); distance += 2; // See explanation in addColumnGapMatch if (distance <= max) { boolean createCell = mGrid.getRowY(mGrid.getRow(matchedLine)) != matchedLine; rowMatches.add( new GridMatch(SegmentType.TOP, distance, matchedLine, rowBottom, createCell, 0)); } } }
/** Adds a baseline match, if applicable. */ private void addBaselineMatch( int dragBaseline, int y1, List<GridMatch> rowMatches, int max, int row, int rowY) { int dragBaselineY = y1 + dragBaseline; int rowBaseline = mGrid.getBaseline(row); if (rowBaseline != -1) { int rowBaselineY = rowY + rowBaseline; int distance = abs(dragBaselineY - rowBaselineY); if (distance < max) { rowMatches.add( new GridMatch(SegmentType.BASELINE, distance, rowBaselineY, row, false, UNDEFINED)); } } }
/** Adds a horizontal match with the center axis of the GridLayout */ private void addCenterColumnMatch( Rect bounds, int x1, int y1, int x2, int y2, List<GridMatch> columnMatches, int max) { Collection<INode> intersectsRow = mGrid.getIntersectsRow(y1, y2); if (intersectsRow.size() == 0) { // Offer centering on this row since there isn't anything there int matchedLine = bounds.centerX(); int distance = abs((x1 + x2) / 2 - matchedLine); if (distance <= 2 * max) { boolean createCell = false; // always just put in column 0 columnMatches.add( new GridMatch( SegmentType.CENTER_HORIZONTAL, distance, matchedLine, 0 /* column */, createCell, UNDEFINED)); } } }
/** * Called when a drop is completed and we're in grid-editing mode. This will insert the dragged * element into the target cell. * * @param targetNode the GridLayout node * @param element the dragged element * @return the newly created node */ public INode handleGridModeDrop(INode targetNode, IDragElement element) { String fqcn = element.getFqcn(); INode newChild = targetNode.appendChild(fqcn); int column = mColumnMatch.cellIndex; if (mColumnMatch.createCell) { mGrid.addColumn(column, newChild, UNDEFINED, false, UNDEFINED, UNDEFINED); } int row = mRowMatch.cellIndex; if (mRowMatch.createCell) { mGrid.addRow(row, newChild, UNDEFINED, false, UNDEFINED, UNDEFINED); } mGrid.setGridAttribute(newChild, ATTR_LAYOUT_COLUMN, column); mGrid.setGridAttribute(newChild, ATTR_LAYOUT_ROW, row); int gravity = 0; if (mColumnMatch.type == SegmentType.RIGHT) { gravity |= GravityHelper.GRAVITY_RIGHT; } else if (mColumnMatch.type == SegmentType.CENTER_HORIZONTAL) { gravity |= GravityHelper.GRAVITY_CENTER_HORIZ; } if (mRowMatch.type == SegmentType.BASELINE) { // There *is* no baseline gravity constant, instead, leave the // vertical gravity unspecified and GridLayout will treat it as // baseline alignment // gravity |= GravityHelper.GRAVITY_BASELINE; } else if (mRowMatch.type == SegmentType.BOTTOM) { gravity |= GravityHelper.GRAVITY_BOTTOM; } else if (mRowMatch.type == SegmentType.CENTER_VERTICAL) { gravity |= GravityHelper.GRAVITY_CENTER_VERT; } if (!GravityHelper.isConstrainedHorizontally(gravity)) { gravity |= GravityHelper.GRAVITY_LEFT; } if (!GravityHelper.isConstrainedVertically(gravity)) { gravity |= GravityHelper.GRAVITY_TOP; } mGrid.setGridAttribute(newChild, ATTR_LAYOUT_GRAVITY, getGravity(gravity)); if (mGrid.declaredColumnCount == UNDEFINED || mGrid.declaredColumnCount < column + 1) { mGrid.setGridAttribute(mGrid.layout, ATTR_COLUMN_COUNT, column + 1); } return newChild; }
/** * 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(); } }
/** * Creates a new {@link GridDropHandler} for * * @param gridLayoutRule the corresponding {@link GridLayoutRule} * @param layout the GridLayout node * @param view the view instance of the grid layout receiving the drop */ public GridDropHandler(GridLayoutRule gridLayoutRule, INode layout, Object view) { mRule = gridLayoutRule; mGrid = GridModel.get(mRule.getRulesEngine(), layout, view); }
/** * Called when a node is dropped in free-form mode. This will insert the dragged element into the * grid and returns the newly created node. * * @param targetNode the GridLayout node * @param element the dragged element * @return the newly created {@link INode} */ public INode handleFreeFormDrop(INode targetNode, IDragElement element) { assert mRowMatch != null; assert mColumnMatch != null; String fqcn = element.getFqcn(); INode newChild = null; Rect bounds = element.getBounds(); int row = mRowMatch.cellIndex; int column = mColumnMatch.cellIndex; if (targetNode.getChildren().length == 0) { // // Set up the initial structure: // // // Fixed Fixed // Size Size // Column Expanding Column Column // +-----+-------------------------------+-----+ // | | | | // | 0,0 | 0,1 | 0,2 | Fixed Size Row // | | | | // +-----+-------------------------------+-----+ // | | | | // | | | | // | | | | // | 1,0 | 1,1 | 1,2 | Expanding Row // | | | | // | | | | // | | | | // +-----+-------------------------------+-----+ // | | | | // | 2,0 | 2,1 | 2,2 | Fixed Size Row // | | | | // +-----+-------------------------------+-----+ // // This is implemented in GridLayout by the following grid, where // SC1 has columnWeight=1 and SR1 has rowWeight=1. // (SC=Space for Column, SR=Space for Row) // // +------+-------------------------------+------+ // | | | | // | SCR0 | SC1 | SC2 | // | | | | // +------+-------------------------------+------+ // | | | | // | | | | // | | | | // | SR1 | | | // | | | | // | | | | // | | | | // +------+-------------------------------+------+ // | | | | // | SR2 | | | // | | | | // +------+-------------------------------+------+ // // Note that when we split columns and rows here, if splitting the expanding // row or column then the row or column weight should be moved to the right or // bottom half! // int columnX = mGrid.getColumnX(column); // int rowY = mGrid.getRowY(row); mGrid.setGridAttribute(targetNode, ATTR_COLUMN_COUNT, 2); // mGrid.setGridAttribute(targetNode, ATTR_COLUMN_COUNT, 3); // INode scr0 = addSpacer(targetNode, -1, 0, 0, 1, 1); // INode sc1 = addSpacer(targetNode, -1, 0, 1, 0, 0); // INode sc2 = addSpacer(targetNode, -1, 0, 2, 1, 0); // INode sr1 = addSpacer(targetNode, -1, 1, 0, 0, 0); // INode sr2 = addSpacer(targetNode, -1, 2, 0, 0, 1); // mGrid.setGridAttribute(sc1, ATTR_LAYOUT_GRAVITY, VALUE_FILL_HORIZONTAL); // mGrid.setGridAttribute(sr1, ATTR_LAYOUT_GRAVITY, VALUE_FILL_VERTICAL); // // mGrid.loadFromXml(); // column = mGrid.getColumn(columnX); // row = mGrid.getRow(rowY); } int startX, endX; if (mColumnMatch.type == SegmentType.RIGHT) { endX = mColumnMatch.matchedLine - 1; startX = endX - bounds.w; column = mGrid.getColumn(startX); } else { startX = mColumnMatch.matchedLine; // TODO: What happens on type=RIGHT? endX = startX + bounds.w; } int startY, endY; if (mRowMatch.type == SegmentType.BOTTOM) { endY = mRowMatch.matchedLine - 1; startY = endY - bounds.h; row = mGrid.getRow(startY); } else if (mRowMatch.type == SegmentType.BASELINE) { // TODO: The rowSpan should always be 1 for baseline alignments, since // otherwise the alignment won't work! startY = endY = mRowMatch.matchedLine; } else { startY = mRowMatch.matchedLine; endY = startY + bounds.h; } int endColumn = mGrid.getColumn(endX); int endRow = mGrid.getRow(endY); int columnSpan = endColumn - column + 1; int rowSpan = endRow - row + 1; // Make sure my math was right: assert mRowMatch.type != SegmentType.BASELINE || rowSpan == 1 : rowSpan; // If the item almost fits into the row (at most N % bigger) then just enlarge // the row; don't add a rowspan since that will defeat baseline alignment etc if (!mRowMatch.createCell && bounds.h <= MAX_CELL_DIFFERENCE * mGrid.getRowHeight(mRowMatch.type == SegmentType.BOTTOM ? endRow : row, 1)) { if (mRowMatch.type == SegmentType.BOTTOM) { row += rowSpan - 1; } rowSpan = 1; } if (!mColumnMatch.createCell && bounds.w <= MAX_CELL_DIFFERENCE * mGrid.getColumnWidth( mColumnMatch.type == SegmentType.RIGHT ? endColumn : column, 1)) { if (mColumnMatch.type == SegmentType.RIGHT) { column += columnSpan - 1; } columnSpan = 1; } if (mColumnMatch.type == SegmentType.CENTER_HORIZONTAL) { column = 0; columnSpan = mGrid.actualColumnCount; } // Temporary: Ensure we don't get in trouble with implicit positions mGrid.applyPositionAttributes(); // Split cells to make a new column if (mColumnMatch.createCell) { int columnWidthPx = mGrid.getColumnDistance(column, mColumnMatch.matchedLine); // assert columnWidthPx == columnMatch.distance; // TBD? IF so simplify int columnWidthDp = mRule.getRulesEngine().pxToDp(columnWidthPx); int maxX = mGrid.getColumnMaxX(column); boolean insertMarginColumn = false; if (mColumnMatch.margin == 0) { columnWidthDp = 0; } else if (mColumnMatch.margin != UNDEFINED) { int distance = abs(mColumnMatch.matchedLine - (maxX + mColumnMatch.margin)); insertMarginColumn = column > 0 && distance < 2; if (insertMarginColumn) { int margin = mColumnMatch.margin; if (ViewMetadataRepository.INSETS_SUPPORTED) { IViewMetadata metadata = mRule.getRulesEngine().getMetadata(fqcn); if (metadata != null) { Margins insets = metadata.getInsets(); if (insets != null) { // TODO: // Consider left or right side attachment // TODO: Also consider inset of element on cell to the left margin -= insets.left; } } } columnWidthDp = mRule.getRulesEngine().pxToDp(margin); } } column++; mGrid.splitColumn(column, insertMarginColumn, columnWidthDp, mColumnMatch.matchedLine); if (insertMarginColumn) { column++; } } // Split cells to make a new row if (mRowMatch.createCell) { int rowHeightPx = mGrid.getRowDistance(row, mRowMatch.matchedLine); // assert rowHeightPx == rowMatch.distance; // TBD? If so simplify int rowHeightDp = mRule.getRulesEngine().pxToDp(rowHeightPx); int maxY = mGrid.getRowMaxY(row); boolean insertMarginRow = false; if (mRowMatch.margin == 0) { rowHeightDp = 0; } else if (mRowMatch.margin != UNDEFINED) { int distance = abs(mRowMatch.matchedLine - (maxY + mRowMatch.margin)); insertMarginRow = row > 0 && distance < 2; if (insertMarginRow) { int margin = mRowMatch.margin; IViewMetadata metadata = mRule.getRulesEngine().getMetadata(element.getFqcn()); if (metadata != null) { Margins insets = metadata.getInsets(); if (insets != null) { // TODO: // Consider left or right side attachment // TODO: Also consider inset of element on cell to the left margin -= insets.top; } } rowHeightDp = mRule.getRulesEngine().pxToDp(margin); } } row++; mGrid.splitRow(row, insertMarginRow, rowHeightDp, mRowMatch.matchedLine); if (insertMarginRow) { row++; } } // Figure out where to insert the new child int index = mGrid.getInsertIndex(row, column); if (index == -1) { // Couldn't find a later place to insert newChild = targetNode.appendChild(fqcn); } else { GridModel.ViewData next = mGrid.getView(index); newChild = targetNode.insertChildAt(fqcn, index); // Must also apply positions to the following child to ensure // that the new child doesn't affect the implicit numbering! // TODO: We can later check whether the implied number is equal to // what it already is such that we don't need this next.applyPositionAttributes(); } // Set the cell position (gravity) of the new widget int gravity = 0; if (mColumnMatch.type == SegmentType.RIGHT) { gravity |= GravityHelper.GRAVITY_RIGHT; } else if (mColumnMatch.type == SegmentType.CENTER_HORIZONTAL) { gravity |= GravityHelper.GRAVITY_CENTER_HORIZ; } mGrid.setGridAttribute(newChild, ATTR_LAYOUT_COLUMN, column); if (mRowMatch.type == SegmentType.BASELINE) { // There *is* no baseline gravity constant, instead, leave the // vertical gravity unspecified and GridLayout will treat it as // baseline alignment // gravity |= GravityHelper.GRAVITY_BASELINE; } else if (mRowMatch.type == SegmentType.BOTTOM) { gravity |= GravityHelper.GRAVITY_BOTTOM; } else if (mRowMatch.type == SegmentType.CENTER_VERTICAL) { gravity |= GravityHelper.GRAVITY_CENTER_VERT; } // Ensure that we have at least one horizontal and vertical constraint, otherwise // the new item will be fixed. As an example, if we have a single button in the // table which we inserted *without* a gravity, and we then insert a button // above it with a vertical gravity, then only the top column would be considered // stretchable, and it will fill all available vertical space and the previous // button will jump to the bottom. if (!GravityHelper.isConstrainedHorizontally(gravity)) { gravity |= GravityHelper.GRAVITY_LEFT; } /* This causes problems: Try placing two buttons vertically from the top of the layout. We need to solve the free column/free row problem first. if (!GravityHelper.isConstrainedVertically(gravity) // There is no baseline constant, so we have to leave it unconstrained instead && mRowMatch.type != SegmentType.BASELINE // You also can't baseline align one element with another that has vertical // alignment top or bottom, so when we first "freely" place views (e.g. // at a particular y location), also place it freely (no constraint). && !mRowMatch.createCell) { gravity |= GravityHelper.GRAVITY_TOP; } */ mGrid.setGridAttribute(newChild, ATTR_LAYOUT_GRAVITY, getGravity(gravity)); mGrid.setGridAttribute(newChild, ATTR_LAYOUT_ROW, row); // Apply spans to ensure that the widget can fit without pushing columns if (columnSpan > 1) { mGrid.setGridAttribute(newChild, ATTR_LAYOUT_COLUMN_SPAN, columnSpan); } if (rowSpan > 1) { mGrid.setGridAttribute(newChild, ATTR_LAYOUT_ROW_SPAN, rowSpan); } // Ensure that we don't store columnCount=0 if (mGrid.actualColumnCount == 0) { mGrid.setGridAttribute(mGrid.layout, ATTR_COLUMN_COUNT, Math.max(1, column + 1)); } return newChild; }
/** Adds a match to align the top edge with some other edge. */ private void addTopMatch(int y1, List<GridMatch> rowMatches, int max, int row, int rowY) { int distance = mGrid.getRowDistance(row, y1); if (distance <= max) { rowMatches.add(new GridMatch(SegmentType.TOP, distance, rowY, row, false, UNDEFINED)); } }