Automatic detection of images from PDF

Question

I use PSPDFKit for iOS.

In a PSPDFViewController witch conforms PSPDFViewControllerDelegate I overwrite -(BOOL)pdfViewController didTapOnPageView: atPoint:(CGPoint)viewPoint, and I need to check if any image [pageView.textParser.images] from that page was clicked on.

How do I match the coordinates of my point [viewPoint] with the coordinates of the image?

In short, I want to implement an automatic detection of images in pdf.

Answer 1

UPDATE: I found the answer in PSPDFKIT examples,

- (void)pdfViewController:(PSPDFViewController *)pdfController didLoadPageView:(PSPDFPageView *)pageView {
    // Iterate over all images and add button overlays on top.
    // Accessing the text parser will block the thread, so it'll be better to access the in a background thread and than use the result on the main thread (but then you'll have to check if the pageView still points at the same page which would add too much complexity for this simple example.)
    for (PSPDFImageInfo *imageInfo in [pageView.document textParserForPage:pageView.page].images) {
        // Create the view
        PSCAutoResizeButton *resizeButton = [PSCAutoResizeButton new];
        resizeButton.targetPDFRect = [imageInfo boundingBox];
        resizeButton.imageInfo = imageInfo;
        resizeButton.showsTouchWhenHighlighted = NO;
        resizeButton.layer.borderColor = [UIColor redColor].CGColor;
        resizeButton.layer.borderWidth = 0.f;
        resizeButton.backgroundColor = [UIColor colorWithWhite:0.f alpha:0.2f];
        [resizeButton addTarget:self action:@selector(imageButtonPressed:) forControlEvents:UIControlEventTouchUpInside];
        // Add to container view. Only here views will get notified on changes via PSPDFAnnotationViewProtocol.
        // The container view will be purged when the page is prepared for reusage.
        [pageView.annotationContainerView addSubview:resizeButton];
    } }

---

Private

- (void)imageButtonPressed:(PSCAutoResizeButton *)button {
    NSParameterAssert([button isKindOfClass:PSCAutoResizeButton.class]);

    PSPDFImageInfo *imageInfo = button.imageInfo;
    UIImage *image = [imageInfo imageWithError:NULL];

    // Show view controller
    if (image) {
        UIViewController *imagePreviewController = [[UIViewController alloc] initWithNibName:nil bundle:nil];
        imagePreviewController.title = imageInfo.imageID;
        UIImageView *imageView = [[UIImageView alloc] initWithImage:image];
        imageView.contentMode = UIViewContentModeScaleAspectFit;
        imageView.backgroundColor = UIColor.blackColor;
        imagePreviewController.view = imageView;
        [self presentModalOrInPopover:imagePreviewController embeddedInNavigationController:YES withCloseButton:YES animated:YES sender:button options:@{PSPDFPresentOptionAlwaysModal : @YES, PSPDFPresentOptionModalPresentationStyle : @(UIModalPresentationFormSheet)}];
    } }