I would like to implement karaoke-like progress highlight for iOS.
I know I could use NSAttributedString and highlight the text character by character. However, I would like the highlight to progress pixel by pixel, not character by character.
Any ideas?
P.S. No need for sample code, just point me to the right direction.
Here is an example:
I can't think of any automatic way to do that. There would be several problems to solve. It would be pretty hard, I think.
The hardest would probably be figuring out the pixel position of each word so you can pace the coloring to match the timing within the music. With text and attributed layout, you could probably get the text engine to give you the boundaries of each word and then apply the color attribute to each word as it's spoken/sung. You'd have to have data about the time offset for the beginning and end of each word's being sung.
You might have to use Core Text to get layout information about the bounding rectangles of each word.
Once you get that you could build a path (UIBezierPath or CGPath; they're pretty interchangeable) that follows the flow of the text, and then install that path in to a shape layer. You could then make the text transparent, make the shape layer a colored background that shows through, and animate the shape layer's strokeStart and/or strokeEnd properties to make it fill the text. You might need to do it word by word with a short animation that interpolates between one word and the next to get the timing right.
You probably want to have a look at Core Text, which is the lower level framework used for laying out text, using this you can obtain necessary paths that you need to render said effect (I suggest starting from answers similar to this)
There are plenty of answers for alternative, perhaps simpler answers, for example character by character or word-by-word, which may be easier to implement.
Related
I am trying to draw an NSAttributedString (actually, a constructed NSMutableAttributedString) where the "original" text has been struck and replacement text inserted above it (I'm trying to replicate the look/feel of an Ancient Greek manuscript).
My technique is a combination of NSBaselineOffsetAttributeName with NSKernAttributeName, but it appears that using a negative value for NSKernAttributeName "wipes away" the strikethrough of the text, even if the characters don't overlap.
If I put an extra space after the "A" character (in the original text), the "A" gets the strikethrough, but the "EI" is also offset to the right. So, it appears that the offset/kerning of the "EI" text affects how much of the strikethrough actually occurs.
Here's what I'd like to reproduce (I don't care about the angle; it's not about a picture-perfect reproduction; just the gist):
Here's what is currently happening:
This is when I add an extra space after the strikethrough:
So, the only other thing I can think of would be to render a separate NSAttributedString in the correct place, separate from the current one, but I have no idea how to calculate the location of a specific character in an NSAttributedString when it's drawn. I'm drawing to a PDF, not to any on-screen control like a UILabel. Alternatively, I could draw the "strikethrough" myself as a line, but that seems to still require knowing the coordinates for the text in question, which is calculated on-the-fly, and I hope to use this method to reproduce a large sample of ancient texts, which means doing it by hand just isn't a good answer here.
Anything I'm missing, or any out-of-the-box ideas to try?
In OpenLayers I use ol.style.Text to add a text label to federal states polygons. The states have names of different length and also polygons of different sizes. It looks like this:
Is it possible to only print the text marker if it fits inside its polygon (e.g. after zooming in)? For instance, in the above example Hessen, Thüringen, Sachsen and Bayern would be printed, but Rheinland-Pfalz, Saarland and Baden-Württemberg would be omitted because the text goes beyond its feature's geometry...
I know I can set the font property of an ol.style.Text to a particular size based on the resolution but this does not help here as text would still overlap the borders sometimes...
This is currently not possible with help from the library. But you can use CanvasRenderingContext2D#measureText() in your vector layer's stlyeFunction to get the width of the label, and compare that with the extent's width of the polygon at a certain resolution, and decide based on that whether to render or not. You can also get smarter than using the extent's width, but it is probably a good enough approximation for many cases.
I am creating a game board using Expression Blend with lots of irregular shapes. These shapes will have text blocks on them as labels. For a given shape and its text block, I want them to behave as one control. An example: on a blackjack table the "Insurance" betting area is a curved area with text that reads "Insurance Pays 2 to 1". What is the best way to make those to behave as one control? In this example, if I drag a chip on to either control - the text of the betting area - it should respond the same way. Would it be to make it into a user control? If not, what is a better way to accomplish this?
Answered over on Expression Forum for anyone else it helps. :)
http://social.expression.microsoft.com/Forums/en/blend/thread/4e640536-043b-4717-ab9a-73c309485af9
I'm attempting to draw a richly laid out text view on iPhone that features:
Custom paragraph spacing (kCTParagraphStyleSpecifierParagraphSpacing)
Custom paragraph first-line indentation (kCTParagraphStyleSpecifierFirstLineHeadIndent)
Justified alignment (kCTParagraphStyleSpecifierAlignment)
Finally, a drop cap on my first paragraph
I'm using OHAttributedLabel. The first three points I achieved without much trouble by just setting some paragraph style attributes on my NSAttributedString.
The drop cap I managed to implement by hacking OHAttributedLabel:
Cut out a rectangular region out of the main paragraph's CGMutablePathRef the size of the drop cap by adding an extra CGPathAddRect, as detailed in this excellent blog post.
Drawing the large character in this region with an extra CTFrameDraw call.
My problem: The paragraph styles and the custom text path are incompatible. When I cut a rectangular chunk out of the main text's path, all the paragraph styles seem to get thrown away.
Does anyone know a way to make them work together? Or can anyone think of another way to implement drop caps? (Short of using a UIWebView + CSS, which I'd rather not have the overhead of!)
Thanks!
You can use straight Core Text to achieve this, in the following post I explain the use of 2 framesetters to lay out text with drop caps in a UIView. In the code example (there's also a link to a github repo) you'll be able to see where the paragraph styles are created and applied to the main text view.
https://stackoverflow.com/a/14639864/1218605
How can I fully justify a block of text (like MS Word does, not only on the right and not only on the left but on both sides)?
I want to justify some texts (mainly arabic text) adjusted to certain screen size (some handheld device screen actually, and its text viewer doesn't have this function) and save this text as justified. So I can reload and reuse it again elsewhere.
(The problem with MS word is, that if you copy the justified text from MS Word and paste it to another editor it'll copy it un-justified).
Update : for now I'm thinking of doing it like this:
get-a-word
get-word-width
add-word-to-total-Word and add-Word-width-to-total-word-width
check if total-Word-width = myscreen-width then continue
else if total-Word-width is between myscree-wdith and (myscreen-width -3) then
add-spaces-To-total-word until it = myscreen-width
This is what I'm thinking now, but I put this question up and hope to see if there is a better solution, or somebody else already implemented it.
PS: I hope I have made my question clear and I'm sorry for bad expression if there is.
edit1 : changed the title to make it more clear.
If you want to justify plain text, you can only add extra spaces to the lines to get them align on the left and right. Unfortunately the character widths differ in fonts; so doing it this way will only work for a certain font, unless you limit yourself to monospaced fonts where all characters have the same size.
If you want a result like in Word, adding spaces won't cut it. Word will not add spaces, but stretch and shrink the existing spaces. This information is lost when you copy and paste it into another app.
Either way, justifying is an optimization problem. If you are interested in a good solution and its implementation: have a look a TeX. For an implementation that works on plain text with monospaced fonts have a look at par
There are some API calls that may help:
ExtTextOut and GetCharacterPlacement
Look at the GCP_JUSTIFY flag for GetCharacterPlacement
ExtTextOut is used by Canvas.TextRect
The problem you are going to face is always going to be differences in the rendering of the font. Word handles full justification by adjusting kerning as well as adjusting the number of pixels between words by a few (either way). The end result is lined up both margins. This pixel adjustment is done BOTH ways, and as evenly as possible.
To properly handle this in your portable device you will have to also perform the same algorithm for the display of the text there.
If this is not possible, then the ONLY way you can even get somewhat close would be to add whitespace between words.
As has been pointed out in other answers Word does full justification by stretching the existing spaces often by very small amounts. This is only possible if you have full control over how your text is drawn on the screen (which word - or any other windows program has).
You only real option in this regard would be to implement your own text viewer on the platform you are targeting. Eg you would need to draw the text on the screen yourself (any platform that allows games should allow you to draw on the screen). However this seems like an awful lot of trouble to get justified text.
Sorry couldn't be of more help.