ATPagingView: allow to set the page index

andreyvit · Apr 26, 2011 · b69e6fe · b69e6fe
1 parent ba5bee4
commit b69e6fe
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Showing 3 changed files with 32 additions and 2 deletions.
diff --git a/ATPagingView/ATPagingView.h b/ATPagingView/ATPagingView.h
@@ -39,7 +39,7 @@
 
 @property(nonatomic, readonly) NSInteger pageCount;
 
-@property(nonatomic, assign, readonly) NSInteger currentPageIndex;
+@property(nonatomic, assign) NSInteger currentPageIndex;
 @property(nonatomic, assign, readonly) NSInteger previousPageIndex; // only for reading inside currentPageDidChangeInPagingView
 
 @property(nonatomic, assign, readonly) NSInteger firstVisiblePageIndex;

diff --git a/ATPagingView/ATPagingView.m b/ATPagingView/ATPagingView.m
@@ -5,6 +5,9 @@
 #import "ATPagingView.h"
 
 
+//#define AT_PAGING_VIEW_TRACE_LAYOUT
+
+
 @interface ATPagingView () <UIScrollViewDelegate>
 
 - (void)configurePages;
@@ -51,7 +54,7 @@ - (void)commonInit {
     // someone uses ATPagingView in a non-fullscreen layout.
     self.clipsToBounds = YES;
 
-    _scrollView = [[UIScrollView alloc] initWithFrame:CGRectZero];
+    _scrollView = [[UIScrollView alloc] initWithFrame:[self frameForScrollView]];
     _scrollView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
     _scrollView.pagingEnabled = YES;
     _scrollView.backgroundColor = [UIColor blackColor];
@@ -137,11 +140,23 @@ - (void)configurePages {
 
     CGSize contentSize = CGSizeMake(_scrollView.frame.size.width * _pageCount, _scrollView.frame.size.height);
     if (!CGSizeEqualToSize(_scrollView.contentSize, contentSize)) {
+#ifdef AT_PAGING_VIEW_TRACE_LAYOUT
+        NSLog(@"configurePages: _scrollView.frame == %@, setting _scrollView.contentSize = %@",
+              NSStringFromCGRect(_scrollView.frame), NSStringFromCGSize(contentSize));
+#endif
         _scrollView.contentSize = contentSize;
+        _scrollView.contentOffset = CGPointMake(_scrollView.frame.size.width * _currentPageIndex, 0);
+    } else {
+#ifdef AT_PAGING_VIEW_TRACE_LAYOUT
+        NSLog(@"configurePages: _scrollView.frame == %@", NSStringFromCGRect(_scrollView.frame));
+#endif
     }
 
     CGRect visibleBounds = _scrollView.bounds;
     NSInteger newPageIndex = MIN(MAX(floorf(CGRectGetMidX(visibleBounds) / CGRectGetWidth(visibleBounds)), 0), _pageCount - 1);
+#ifdef AT_PAGING_VIEW_TRACE_LAYOUT
+    NSLog(@"newPageIndex == %d", newPageIndex);
+#endif
 
     // calculate which pages are visible
     int firstVisiblePage = self.firstVisiblePageIndex;
@@ -266,6 +281,20 @@ - (void)didRotate {
 }
 
 
+#pragma mark -
+#pragma mark Page navigation
+
+- (void)setCurrentPageIndex:(NSInteger)newPageIndex {
+#ifdef AT_PAGING_VIEW_TRACE_LAYOUT
+    NSLog(@"setCurrentPageIndex(%d): _scrollView.frame == %@", newPageIndex, NSStringFromCGRect(_scrollView.frame));
+#endif
+    if (_scrollView.frame.size.width > 0 && fabsf(_scrollView.frame.origin.x - (-_gapBetweenPages/2)) < 1e-6)
+        _scrollView.contentOffset = CGPointMake(_scrollView.frame.size.width * newPageIndex, 0);
+    else
+        _currentPageIndex = newPageIndex;
+}
+
+
 #pragma mark -
 #pragma mark Layouting
 

diff --git a/ATPagingView/ATPagingViewDemo/Classes/DemoViewController.m b/ATPagingView/ATPagingViewDemo/Classes/DemoViewController.m
@@ -14,6 +14,7 @@ - (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interface
 
 - (void)viewWillAppear:(BOOL)animated {
     [super viewWillAppear:animated];
+    self.pagingView.currentPageIndex = 3;
     [self currentPageDidChangeInPagingView:self.pagingView];
 }