UIWebView长按图片生成保存菜单

转载自:  http://zl4393753.iteye.com/blog/1752135

UIWebView长按图片生成保存菜单 
参考： 
http://www.icab.de/blog/2010/07/11/customize-the-contextual-menu-of-uiwebview/ 
http://www.icab.de/blog/2011/10/17/elementfrompoint-under-ios-5/comment-page-1/#comment-30184 

自定义UILongPressGestureRecognizer 
创建 UnpreventableUILongPressGestureRecognizer.h 

C代码  

1. #import <Foundation/Foundation.h>  
2. @interface UnpreventableUILongPressGestureRecognizer : UILongPressGestureRecognizer {  
3. }  
4. @end  

UnpreventableUILongPressGestureRecognizer.m 

C代码  

1. #import "UnpreventableUILongPressGestureRecognizer.h"  
2.    
3. @implementation UnpreventableUILongPressGestureRecognizer  
4. - (BOOL)canBePreventedByGestureRecognizer:(UIGestureRecognizer *)preventedGestureRecognizer {  
5.     return NO;  
6. }  
7. @end  

UIWebview页面给webview添加手势 ViewController.m： 

C代码  

1. UnpreventableUILongPressGestureRecognizer *longPressRecognizer = [[UnpreventableUILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(handleLongPress:)];  
2. longPressRecognizer.allowableMovement = 20;  
3. longPressRecognizer.minimumPressDuration = 1.0f;  
4. [webview addGestureRecognizer:longPressRecognizer];  

ViewController.m 处理手势： 

C代码  

1. -(void)handleLongPress:(UILongPressGestureRecognizer *)gestureRecognizer  
2. {  
3.     if (gestureRecognizer.state == UIGestureRecognizerStateBegan) {  
4.            
5.         CGPoint pt = [gestureRecognizer locationInView:self.webview];  
6.            
7.         // convert point from view to HTML coordinate system  
8.         // 뷰의 포인트 위치를 HTML 좌표계로 변경한다.  
9.         CGSize viewSize = [webview frame].size;  
10.         CGSize windowSize = [webview windowSize];  
11.         CGFloat f = windowSize.width / viewSize.width;  
12.    
13.         if ([[[UIDevice currentDevice] systemVersion] doubleValue] >= 5.0) {  
14.             pt.x = pt.x * f;  
15.             pt.y = pt.y * f;  
16.         } else {  
17.             // On iOS 4 and previous, document.elementFromPoint is not taking  
18.             // offset into account, we have to handle it  
19.             CGPoint offset = [webview scrollOffset];  
20.             pt.x = pt.x * f + offset.x;  
21.             pt.y = pt.y * f + offset.y;  
22.         }  
23.            
24.         [self openContextualMenuAt:pt];  
25.     }  
26. }  

创建分类 WebViewAdditions.h 

C代码  

1. #import <foundation foundation.h="">  
2. @interface UIWebView(WebViewAdditions)  
3. - (CGSize)windowSize;  
4. - (CGPoint)scrollOffset;  
5. @end  
6. </foundation>  

WebViewAdditions.m 

C代码  

1. #import "WebViewAdditions.h"  
2.    
3. @implementation UIWebView(WebViewAdditions)  
4.    
5. - (CGSize)windowSize  
6. {  
7.     CGSize size;  
8.     size.width = [[self stringByEvaluatingJavaScriptFromString:@"window.innerWidth"] integerValue];  
9.     size.height = [[self stringByEvaluatingJavaScriptFromString:@"window.innerHeight"] integerValue];  
10.     return size;  
11. }  
12.    
13. - (CGPoint)scrollOffset  
14. {  
15.     CGPoint pt;  
16.     pt.x = [[self stringByEvaluatingJavaScriptFromString:@"window.pageXOffset"] integerValue];  
17.     pt.y = [[self stringByEvaluatingJavaScriptFromString:@"window.pageYOffset"] integerValue];  
18.     return pt;  
19. }  
20. @end  

弹出菜单 ViewController.m 

C代码  

1. - (void)openContextualMenuAt:(CGPoint)pt{  
2.     // Load the JavaScript code from the Resources and inject it into the web page  
3.     NSBundle *bundle = [NSBundle bundleWithPath:[[NSBundle mainBundle] pathForResource:@"Naving" ofType:@"bundle"]];  
4.     NSString *path = [bundle pathForResource:@"JSTools" ofType:@"js"];  
5.     NSString *jsCode = [NSString stringWithContentsOfFile:path encoding:NSUTF8StringEncoding error:nil];  
6.     [webview stringByEvaluatingJavaScriptFromString:jsCode];  
7.        
8.     // get the Tags at the touch location  
9.     NSString *tags = [webview stringByEvaluatingJavaScriptFromString:  
10.                       [NSString stringWithFormat:@"MyAppGetHTMLElementsAtPoint(%i,%i);",(NSInteger)pt.x,(NSInteger)pt.y]];  
11.        
12.     NSString *tagsHREF = [webview stringByEvaluatingJavaScriptFromString:  
13.                           [NSString stringWithFormat:@"MyAppGetLinkHREFAtPoint(%i,%i);",(NSInteger)pt.x,(NSInteger)pt.y]];  
14.        
15.     NSString *tagsSRC = [webview stringByEvaluatingJavaScriptFromString:  
16.                          [NSString stringWithFormat:@"MyAppGetLinkSRCAtPoint(%i,%i);",(NSInteger)pt.x,(NSInteger)pt.y]];  
17.        
18.     NSLog(@"tags : %@",tags);  
19.     NSLog(@"href : %@",tagsHREF);  
20.     NSLog(@"src : %@",tagsSRC);  
21.        
22.     if (!_actionActionSheet) {  
23.         _actionActionSheet = nil;  
24.     }  
25.     _actionActionSheet = [[UIActionSheet alloc] initWithTitle:nil  
26.                                                        delegate:self  
27.                                               cancelButtonTitle:nil  
28.                                          destructiveButtonTitle:nil  
29.                                               otherButtonTitles:nil];  
30.        
31.     selectedLinkURL = @"";  
32.     selectedImageURL = @"";  
33.        
34.     // If an image was touched, add image-related buttons.  
35.     if ([tags rangeOfString:@",IMG,"].location != NSNotFound) {  
36.         selectedImageURL = tagsSRC;  
37.            
38.         if (_actionActionSheet.title == nil) {  
39.             _actionActionSheet.title = tagsSRC;  
40.         }  
41.            
42.         [_actionActionSheet addButtonWithTitle:@"Save Image"];  
43.         [_actionActionSheet addButtonWithTitle:@"Copy Image"];  
44.     }  
45.     // If a link is pressed add image buttons.  
46.     if ([tags rangeOfString:@",A,"].location != NSNotFound){  
47.         selectedLinkURL = tagsHREF;  
48.            
49.         _actionActionSheet.title = tagsHREF;  
50.         [_actionActionSheet addButtonWithTitle:@"Open Link"];  
51.         [_actionActionSheet addButtonWithTitle:@"Copy Link"];  
52.     }  
53.        
54.     if (_actionActionSheet.numberOfButtons > 0) {  
55.         [_actionActionSheet addButtonWithTitle:@"Cancel"];  
56.         _actionActionSheet.cancelButtonIndex = (_actionActionSheet.numberOfButtons-1);  
57.            
58.            
59.         [_actionActionSheet showInView:webview];  
60.     }  
61.        
62. }  

工具文件 JSTools.js 

Js代码  

1. function MyAppGetHTMLElementsAtPoint(x,y) {  
2.     var tags = ",";  
3.     var e = document.elementFromPoint(x,y);  
4.     while (e) {  
5.         if (e.tagName) {  
6.             tags += e.tagName + ',';  
7.         }  
8.         e = e.parentNode;  
9.     }  
10.     return tags;  
11. }  
12.    
13. function MyAppGetLinkSRCAtPoint(x,y) {  
14.     var tags = "";  
15.     var e = document.elementFromPoint(x,y);  
16.     while (e) {  
17.         if (e.src) {  
18.             tags += e.src;  
19.             break;  
20.         }  
21.         e = e.parentNode;  
22.     }  
23.     return tags;  
24. }  
25.    
26. function MyAppGetLinkHREFAtPoint(x,y) {  
27.     var tags = "";  
28.     var e = document.elementFromPoint(x,y);  
29.     while (e) {  
30.         if (e.href) {  
31.             tags += e.href;  
32.             break;  
33.         }  
34.         e = e.parentNode;  
35.     }  
36.     return tags;  
37. }  

ViewController.m 处理ActionSheet事件 

C代码  

1. #pragma UIActionSheetDelegate  
2. -(void)actionSheet:(UIActionSheet *)actionSheet clickedButtonAtIndex:(NSInteger)buttonIndex{  
3.     if ([[actionSheet buttonTitleAtIndex:buttonIndex] isEqualToString:@"Open Link"]){  
4.         [webview loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:selectedLinkURL]]];  
5.     }  
6.     else if ([[actionSheet buttonTitleAtIndex:buttonIndex] isEqualToString:@"Copy Link"]){  
7.         [[UIPasteboard generalPasteboard] setString:selectedLinkURL];  
8.     }  
9.     else if ([[actionSheet buttonTitleAtIndex:buttonIndex] isEqualToString:@"Copy Image"]){  
10.         [[UIPasteboard generalPasteboard] setString:selectedImageURL];  
11.     }  
12.     else if ([[actionSheet buttonTitleAtIndex:buttonIndex] isEqualToString:@"Save Image"]){  
13.         NSOperationQueue *queue = [NSOperationQueue new];  
14.         NSInvocationOperation *operation = [[NSInvocationOperation alloc] initWithTarget:self  
15.                                                                                 selector:@selector(saveImageURL:) object:selectedImageURL];  
16.         [queue addOperation:operation];  
17.         //[operation release];  
18.     }  
19. }  
20.    
21. -(void)saveImageURL:(NSString*)url{  
22.     [self performSelectorOnMainThread:@selector(showStartSaveAlert)   
23.                            withObject:nil  
24.                         waitUntilDone:YES];  
25.        
26.     UIImageWriteToSavedPhotosAlbum([UIImage imageWithData:[NSData dataWithContentsOfURL:[NSURL URLWithString:url]]], nil, nil, nil);  
27.        
28.     [self performSelectorOnMainThread:@selector(showFinishedSaveAlert)  
29.                            withObject:nil  
30.                         waitUntilDone:YES];  
31. }