I've loaded a PDF Document into a UIView Class, and displayed it on screen using CGDrawRect. So Now I can visually see the PDF: What I want to do is have the user click certain points of the file, which will bring up the key board, allowing the user to directly add text to the PDF, which will later need to be rendered - some direction or guide would be very helpful ?
I understand its a lot simpler to draw a PDF from scratch then to manipulate it
I also understand Quartz 2d may be the way to go, but a bit confused with the samples
There are two possible scenarios here:
Editing existing PDF text is very difficult, even with something like PSPDFKit. It is no accident that there are no PDF-based word processors.
Annotating PDF content is more straightforward:
Add any additional content as subviews to the UIView that contains the PDF document. Additional content can be in the form of text, vectors or images - anything that can be added to a UIView. At this point you do not need to worry whether the added content is "part of" the PDF.
When you want to render the added content to the PDF, simply render the container view (which contains both the original document and annotations) to a PDF Context using UIGraphicsBeginPDFContextToFile and UIGraphicsBeginPDFPage.
Check this question and answer for a simple example and a method for ensuring that the PDF is rendered as vectors, not as a bitmap: Rendering a UIView into a PDF as vectors on an iPad - Sometimes renders as bitmap, sometimes as vectors
Related
I am using VS2013Express to create a windows form based application which will display and eventually print Visio documents, rather than relying on the browser based Visio Viewer. Needless to say this is a very specific requirement, so really don't need anyone telling me to use the MS Visio Viewer!
So far, I can open the Visio document, display it using the AxVisioViewer.dll control. I can even print... to a degree.
The issue is that I can only print currently using a PrintFromScreen method which basically captures the image of the form as displayed on screen and creates a Raster BitMap of it.
I copy the BitMap image to a hidden panel on the form (to remove toolbars etc), then print the contents of the panel. Simple (ish)!
Here's a link to the page I used to create the panel and print the image.
What I want to be able to do is resize (Vector not Raster to retain scale) and centre the image as required to ensure the document prints properly.
You'll want to center the drawing in the control.
Check the following link.
https://msdn.microsoft.com/en-us/vba/visio-vba/articles/viewer-zoomtorect-method-visio-viewer
You may also check the zoom and pan methods.
I am currently working on an app where we would like to download a PDF from a remote server and then draw on it. We would like to draw Google Maps pin-like annotations on the PDF (the static draw part). Furthermore, we would like to detect if a user has touched a pin and then draw a calloutBox over this PDF (dynamic draw part). We obviously would like the pdf to be scrollable/zoomable. Does anyone know of a good way to achieve this?
Things I have researched:
1) Render in a UIWebView. This seems like a great solution but its not clear to me how to then implement the draw code on the PDF. I have heard people say create a transparent UIView above the UIWebView for the drawing. This seems to come with its issues, how will it handle zooming and scrolling?
2) Use Quartz 2D and generate my own PDF from the PDF I fetch from the server. As I draw my own PDF content I can draw the static marker pins. Once I have this PDF, I can then shove it in a WebView. The problem with this approach however is I still need to handle the dynamic drawing of the call-out boxes when a user taps on the pin and this then kinda takes me back to problem 1.
You're correct that Apple does not offer much in terms of this issue. There's UIWebView which can preview and show PDF documents, but it's really not suited to adding annotations, and any "solution" with views will be very fragile, if you manage to do it at all. It's meant as a black box to read PDF documents, not for annotating.
You have to go all the way back to CGContextRef and take over the scrolling, zooming and touch handling/drawing yourself. Apple's ZoomingPDFViewer example is a good start.
I have been working on this problem since 2010 and we offer a commercial solution for PDF annotating for iOS, Android and Web called PSPDFKit. We ship a custom renderer which is better and more exact than Apple's CoreGraphics renderer, but the more interesting part is that we can deal with all common PDF annotation types. You can use note annotations to represent your pins and move them around, add notes, interact/override the default tap handling (and e.g. show your own popover when people tap on them). They are also always the same size - so they can be anchored at an exact point in the PDF and then you can zoom in while they stay the same size. The best part is that this is all part of the PDF spec, so they will also work with Apple's Preview app or Adobe Acrobat, so people can save/customize the markup and then everything can be saved in the PDF. The architecture is flexible so you can also simply save everything in a database or sync it back up to your server and simply use it for touch handling.
You can also build that yourself - the basic architecture is a UIScrollView and views that are managed. It quickly gets tricky when you do zooming and have views that need to stay the same size + touch handling and maybe you also want things like multi-select or regular ink drawing. You will also want to add some sort of image caching layer, since rendering PDF documents can be quite slow on mobile devices. Oh, and if you want to make text selectable or implement search, be ready for a rabbit hole that is called the Adobe CMap and CIDFont
Files Specification.
What I want to do is exporting some data from my app to a text file - say an RTF file. I found that converting text can be done through this classes, but is there a way to save an image also?
If you want to export text + images in the same document you can do it usig Core Graphics. Please search for CGPDFDocument Reference and Quartz 2D Programming Guide in Apple documentation.
However in order to do this you need to have an understanding of the PDF format and you should read the Adobe guide PDF Reference, Fourth Edition, Version 1.5
Using CGPDFContext you can create a UIView, draw your contents into it (using sub views to make life easy for text and images) and then render the views layer into the PDF context. Then save the resulting data to a file.
I am looking at building a simple PDF generator. The user will have several text fields and a couple image fields to enter information, and that will appear in specific spots on the PDF. I know how to add an image already in the app to the PDF, but not sure how to take an image that is chosen from Camera Roll on one view to be in the PDF on the next view. Suggestions?
I have a 92 page catalogue (one image per page, multiple products per image) and no product codes on the image for each product.
Does anyone know of a photoshop action to allow entry of a stock code (<15chars text), that will create a filled, outline box with the text inside? It will be awful to have to do them by hand - there are hundreds and hundreds of products.
If all images have the same code, you could record the action which basically creates a macro of your activity for a single image. (Look for the record/playback buttons on the actions pane.)
If all the images have different codes, you might be better off writing (or commissioning) a small script to process the images, such as a PHP script with GD or C# and a graphics object; in both cases reading from a file so it applies the correct code to the image. However this method wouldn't give you an Adobe Photoshop document at the end of the day with an editable text box; it would be a flattened image (such as a TIFF) with the product code already rendered as part of the image.