I have been using shinobi charts in iOS and I have a line graph in my app - I would now like to add some symbols to the data points and a legend to explain what the symbols mean - If someone could point me to some sample code that would be very helpful.
Thanks.
There is a datasource method which you can use to provide a UIImage for each of the data points:
- (UIImage *)sChartTextureForPoint:(ShinobiChart *)chart
dataPointAtIndex:(NSInteger)dataIndex
forSeriesAtIndex:(NSInteger)seriesIndex
If you implement this then you can provide the symbols as you wish.
The legend is a little more difficult. A legend is usually designed to allow identification of distinct series, however in this instance you would like to identify specific points. This isn't functionality currently supported by Shinobi, and although it would be possible to implement it using the SChartLegend class, I think you would be better off creating your own subclass of UIView as a legend.
Related
I am developing an iPhone application that uses cocos3d. My question is: how to draw custom shape in cocos3d? for example a cylinder, a cylinder with an ellipse as its base instead of a circle, a polygone, etc. Can anyone please guide me how to start?
Thanks in advance
There's good support for doing that in Cocos3D.
CC3Mesh has simple property settings for allocating space for vertex content, plus a large family of methods for getting and setting various vertex content. Make sure you understand how to use the vertexContentTypes property.
The source files CC3ParametricMeshes.m and CC3ParametricMeshNodes.m contain a number of examples of creating mesh shapes programmatically. Have a look at the implementations in those files.
I would like my Scatter graph I am making with Core Plot library to show Y value near every point relative to X data.
I looked at CPTTestApp project from Core Plot examples, but I simply don't get it. First I thought the secret lies in
-(CPTPlotSymbol *)symbolForScatterPlot:(CPTScatterPlot *)plot recordIndex:(NSUInteger)index
method and I have implemented it in my project. Yes, I got points drawn, which is nice, but I found out this probably has nothing to do with values being shown near points....
This suspicion was confirmed when I opened Candlestick demo from Plot_Galley_Mac demo. There is no method from above and it shows numbers nicely!
If anyone can, please, help me. Otherwise, I would like to thank developers for sharing this library with us. Beside over usage of NSDecimal structure and a bit thin manual and reference data, this is fabulous project.
You're looking for "data labels". CPTPlot has a number of properties that control the built-in labeling functions:
labelOffset: distance between the point and the label
labelRotation: rotation angle
labelTextStyle: text style used to draw the labels
labelFormatter: number (or date) formatter used to format the labels
labelShadow: shadow properties applied to the labels
If the built-in labels don't meet your needs, you can create your own. Implement the -dataLabelForPlot:recordIndex: datasource method and return the desired label for each point. Custom labels can be any CPTLayer so you can make anything you want—text, images, or any custom layer that you create.
So I want to have a view (NSView, NSOpenGLView, something CG related?) which basically displays a map. Such as:
http://dump.tanaris4.com/map.png
Obviously that looks horrible, but I did it using an NSView, and it draws SO slow. Clearly not designed for this.
I just need to allow users to click on the individual (x,y) coordinates to make changes, and zoom into a certain area (to see it better).
Should I go the OpenGL route? And if so - any suggestions as to how to get started? (I was able to follow the guide to draw a triangle, so that's good).
I did find this post on zooming in an NSView: How to implement zoom/scale in a Cocoa AppKit-application
My concern is if I'm drawing over 6000 coordinates and the lines connecting them, this isn't efficient at all.
I don't think using OpenGL would be of any good here. The problem does not seem to be the actual painting, but rather the rendering strategy. You would need a scene graph of some kind to dynamically handle level of detail and culling.
Qt has all this packaged in a nice class class QGraphicsScene (see http://doc.qt.nokia.com/latest/qgraphicsscene.html for reference, and http://doc.qt.nokia.com/main-snapshot/demos-chip.html for an example).
Some basic concepts you should consider using:
http://en.wikipedia.org/wiki/Scene_graph
http://en.wikipedia.org/wiki/Quadtree
http://en.wikipedia.org/wiki/Level_of_detail
Try using core graphics for this, really there is so much that could be done. Watch the video Practical Drawing for iOS Developers from WWDC 2011 and it should give an over view of what can be done with CG.
I believe even CoreGraphics will suffice for what you want to achieve, and that should work under a UIView if you draw the rectangle of your view completely under the DrawRect method of your UIView (you must overload this method). Please see the UIView Class Reference. I have a mobile application that logs points on the UIMapKit, kind of like Nike+, and it certainly works well for massive amounts of points/line segments. There is no reason why this simple approach cannot work for you as well.
Hi i'm thinking about making midi step sequencer and I need to make a note grid/matrix that resizes/ adapts when you zoom. I've been searching for different ways of doing this but cant figure out a way that works well.
I thought about drawing cell objects made with (NSRect) but I couldn't figure out how to get the right interaction when resizing.
This is my first "biggish" OBJ-c project so please don't kill me, im still battling with the frameworks and the syntax is so foreign to me.
You could use Core Animation layers to create your grid.
Take a look at Apple's Geek Game Board sample code project:
http://developer.apple.com/library/mac/#samplecode/GeekGameBoard/Introduction/Intro.html
The code shows a way to display different kinds of card/board games using CALayer.
The Checkers game looks to be the closest to the grid you want to create.
I am looking for a way to, in Objective-C, create a PNG from several smaller PNGs based on how the user sets things up. Is this possible using existing Apple classes, or do I need to use a 3rd party library? If 3rd party code is needed, can anyone recommend a good library? The simpler the better - simple filters (such as darkening/lightening the image) would be nice but not required.
Here is some pseudo-code, to give you a better idea of what I am looking for:
image = [myImageLibrary imageWithHeight:1024 width:768];
[image addImage:#"background.png" atX:0 andY:0 withRotation:0];
[image addImage:#"image2.png" atX:100 andY:200 withRotation:90];
[image saveAtLocation:#"output.png"];
At output.png we see image2.png placed on top of background.png and rotated 90 degrees
P.S. - I am sorry if this seems to be a duplicate of another question, I just have not found an answer that works for what I am trying to do.
Have you read the "Creating and Drawing Images" section of the Drawing and Printing Guide for iOS and the UIImage Class Reference docs?
What you're after is perfectly possible - with a well built class you could pretty much use that pseudo code as-is.
As a starter for ten, you could:
Create your own graphics context via UIGraphicsBeginImageContext.
Draw into that via the drawAtPoint: method of the UIImage class
Save the resultant image data out via UIGraphicsGetImageFromCurrentImageContext.
In terms of steps 1 and 3, see the UIKit Function Reference for more info. Additionally, the imageWithCGImage:scale:orientation: method of the UIImage class may prove useful for performing transformations, etc. as a part of step 2.
You'll want to look at CGContextDrawImage to draw your images, using a custom bitmap context, and then save it out using UIGraphicsGetImageFromCurrentImageContext(). The rotation can be done by applying CGAffineTransforms to your CGContext.
More information on Core Graphics here:
http://developer.apple.com/library/mac/#documentation/GraphicsImaging/Conceptual/drawingwithquartz2d/Introduction/Introduction.html