UDBarTrackballItem

Overview

UDBarTrackballItem is a button view for iOS which can position the text cursor (caret) and define the text selection of a text view in parallel to its touch drag movement. The user interaction pattern is similar to a Thinkpad TrackPoint.

The intention was to create a text navigation component for text editor apps that makes the task of frequent text positioning and selection more convenient. The default way of positioning and selection requires a touch down delay to distinguish view scrolling and editing mode as well as the magnifying glass which distract the precise positioning more that it helps. The tradeoff is a decrease in view real-estate for the input accessory view bar (which is quite common in text editors nowadays).

It is implemented as a UIBarButtonItem subclass to control the caret movement and text selection of a UITextView and intended to be use inside a InputAccessoryView (UIToolbar).

Screencast of the sample project example

Features

Single tap dragging cursor (caret) positioning
Double tap dragging text selection
Auto scrolling of text view when positioning out of bound
Auto popup editing menu after positioning or selection
Horizontal side-to-side reach distance without re-tap
Horizontal and vertial layout orientations
Uses ARC and targets iOS 5.0+

Installation

To use UDBarTrackballItem in your own project:

Import UDBarTrackballItem.h and UDBarTrackballItem.m and all png image files into your project
Include UDBarTrackballItem.h (#import "UDBarTrackballItem.h") where needed, or in your precompiled header
Initialize the new UDBarTrackballItem for a UITextView

This project uses ARC and targets iOS 5.0+.

Usage

UDBarTrackballItem *trackballItem = [[UDBarTrackballItem alloc] initForTextView:_textView];
[_toolbar setItems:@[trackballItem] animated:YES];

Credits

Write app for the innovative inspiration for and first-time appearance of this component.

License

This code is distributed under the terms and conditions of the MIT license. Review the full LICENSE for all the details.

Support/Contact

Think you found a bug or just have a feature request? Just post it as an issue, but make sure to review the existing issues first to avoid duplicates. You can also hit me up at @uwe_ for anything else, or to let me know how you're using this component. Thanks!

djui/UDBarTrackballItem