wolf3d-ios/wolf3d/code/iphone/UITableViewScrolling.m

74 lines
2.6 KiB
Objective-C

/*
Copyright (C) 2009-2011 id Software LLC, a ZeniMax Media company.
This file is part of the WOLF3D iOS v2.1 GPL Source Code.
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#import "UITableViewScrolling.h"
#import <UIKit/UITableView.h>
void UITableViewScrollingPageDown( UITableView * table, int totalRows ) {
// If the user taps the page down button, we want to scroll the table view so that the first
// non-visible row becomes visible. To do this, we can get the array of visible index paths,
// find the maximum row within the array, and scroll to the row just after that.
NSArray* visibleIndexPaths = [table indexPathsForVisibleRows];
int maxRow = 0;
for ( NSIndexPath* path in visibleIndexPaths ) {
maxRow = maxRow < path.row ? path.row: maxRow;
}
const int rowToMakeVisible = maxRow + 1;
UITableViewScrollingScrollToRow( table,rowToMakeVisible, totalRows );
}
void UITableViewScrollingPageUp( UITableView * table, int totalRows ) {
// If the user taps the page up button, we want to scroll the table view so that the first
// non-visible row becomes visible. To do this, we can get the array of visible index paths,
// find the minimum row within the array, and scroll to the row just before that.
NSArray* visibleIndexPaths = [table indexPathsForVisibleRows];
int minRow = totalRows - 1;
for ( NSIndexPath* path in visibleIndexPaths ) {
minRow = minRow < path.row ? minRow: path.row;
}
const int rowToMakeVisible = minRow - 1;
UITableViewScrollingScrollToRow( table,rowToMakeVisible, totalRows );
}
void UITableViewScrollingScrollToRow( UITableView * table, int row, int maxRow ) {
const int clampedRowMax = row < maxRow? row: maxRow-1;
const int clampedRow = clampedRowMax < 0? 0: clampedRowMax;
NSIndexPath* pathToMakeVisible = [NSIndexPath indexPathForRow:clampedRow inSection:0];
[table scrollToRowAtIndexPath:pathToMakeVisible atScrollPosition:UITableViewScrollPositionNone animated:YES];
}