fixed possible crash with indexing of instructions; added logic to scroll to top when picking arch;

Author: evilpenguin

ARMRef/ARMRef/Source/Architecture/AArchitectureViewController.m

@@ -75,6 +75,7 @@ - (void) tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath
 
     if (![self.loader.architecture isEqualToString:arch]) {
         BlockSafetyCallWithArgs(self.pickCompletion, arch);
+        
         [self.loader loadArchitecture:arch];
     }
 

ARMRef/ARMRef/Source/CollectionView/ACollectionViewDataHandle.m

@@ -36,7 +36,7 @@ @implementation ACollectionViewDataHandle
 
 - (nonnull __kindof UICollectionViewCell *) collectionView:(nonnull UICollectionView *)collectionView cellForItemAtIndexPath:(nonnull NSIndexPath *)indexPath {
     ACollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:ACollectionViewCell.identifier forIndexPath:indexPath];
-    cell.instruction = self.instructions[indexPath.row];
+    cell.instruction = safetyObjectAtIndex(self.instructions, indexPath.row);
 
     return cell;
 }
@@ -65,7 +65,7 @@ - (void)collectionView:(UICollectionView *)collectionView didUnhighlightItemAtIn
 
 - (CGSize) collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath {
     ACollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:ACollectionViewCell.identifier forIndexPath:indexPath];
-    cell.instruction = self.instructions[indexPath.row];
+    cell.instruction = safetyObjectAtIndex(self.instructions, indexPath.row);
 
     CGFloat maxSize = [cell maxSizeForInstruction:self.instructions[indexPath.row] withWidth:collectionView.bounds.size.width - 20.0f];
 

ARMRef/ARMRef/Source/Defines.h

@@ -48,4 +48,12 @@
 #define BlockSafetyCallWithArgs(block, ...) \
     if (block) block(__VA_ARGS__)
 
+// Array
+#define safetyObjectAtIndex(array, index) \
+    (array.count > index ? array[index] : nil)
+
+#define safetyPointerObjectAtIndex(array, index) \
+    (array.count > index ? [array pointerAtIndex:index] : nil)
+
+
 #endif /* Defines_h */

ARMRef/ARMRef/Source/Main/AMainViewController.m

@@ -104,6 +104,7 @@ - (void) _changeArch:(UIBarButtonItem *)item {
         strongify(self);
 
         [self _showNoDataStyle:YES];
+        [self.collectionView setContentOffset:CGPointZero animated:NO];
     };
 
     [self.navigationController pushViewController:viewController animated:YES];