Tuesday, August 13, 2019

TimeSnapper for Mac is now available!

Since all the way back in 2008, during most of which Windows was my daily-use operating system for work and hobbies, I used, and was a big fan of, a utility called TimeSnapper.  Billing itself as "The Automatic Screenshot Journal", TimeSnapper quietly would run in the system tray of my Windows computer, taking a screenshot of whatever application I was actively using every few seconds.  TimeSnapper additionally came with a "Play Your Day Like a Movie" feature, where I could watch my entire day of work, or jump directly to the screenshot of any point in time of the day.

TimeSnapper saved me on multiple occasions where I would have otherwise lost work. A couple of examples of this:
  • I'd been typing some long-form text into a form on a web page, only to have the browser crash and lose all of my work. Without TimeSnapper's most recent screenshot of my work-in-progress post, I'd have had to recreate the text from scratch, instead of simply having to retype it. (See my 2014 tweet about the incident!)
  • I'd run into a problem with a program, where it displayed a particular error message in a dialog. A few minutes later, I wanted to Google the error to try to find a solution. I couldn't remember the exact text of the error in order to type it into Google... but TimeSnapper had captured an image of the error dialog, so there was no problem!
In early 2017, taking on an assignment with a new product at work, I switched to working on a Mac, making my primary daily-use operating system macOS instead of Windows.  One of the first things I did, naturally, was to look for macOS equivalents of the essential utilities that I had come to rely on for software development and other work on Windows.

Although I was able to find many useful equivalents for utilities such as clipboard history saving, I wasn't able to find anything like TimeSnapper. Seemingly at least once every week after switching to Mac, I'd run into some situation like the ones described above where I wished I could look back in time to retrieve some important piece of information that I know I had on screen a short time earlier, but was now lost.

Fast-forward to the present day, and I'm super excited to announce: The official release of TimeSnapper for Mac is now available!

Why am I able to announce this? Because, in partnership with the original developers of TimeSnapper for Windows, Leon Bambrick and Atli Björgvin Oddsson, I am the developer of TimeSnapper for Mac!

By late 2017, I was frustrated enough with not having TimeSnapper or a similar utility in my day-to-day work that I reached out to Leon, asking if there was any news around a Mac release of TimeSnapper. Leon replied that there was not; but after some conversation, he offered me the opportunity to develop it!

After a long journey, starting with me not even knowing whether making a macOS version of TimeSnapper would be at all possible -- for example, whether macOS even had operating system hooks allowing an application to perform screen captures -- TimeSnapper for Mac is now complete, and is available on Apple's Mac Store as of today!


Some of the major milestones in TimeSnapper for Mac's development, using Objective-C and Xcode, included:
  • Getting a simple, UI-less program working which successfully managed to take and save to disk a screen capture of the Mac desktop.
  • Making the program "wake up" at regular intervals to take screen shots -- and continue to do so even if the computer is put to sleep.
  • The ability to pause, and later resume, the capture of screen shots on command.
  • Adding an option to reduce screen shots in size and/or quality before saving them to disk -- and adding a Preferences window for the user to control these options, as well as the delay between screenshots and the image format (.jpg or .png).

  • An option to capture just the foreground application window, the entire monitor where the application is running, or all monitors (on a multi-monitor system). Due to the way the relevant macOS hooks work, just successfully identifying the foreground-most window was surprisingly challenging, but after lots of effort and testing, TimeSnapper is able to get it right for almost all applications.
  • Adding a "preview image" of a screen shot to the Preferences window with the selected size and quality options applied, as well as an estimate for how large the screen shot would be on disk with the selected options.
  • Adding "auto cleanup" of old screen shots to save disk space, along with Preferences window options for the user to specify a maximum age of saved screen shots, and/or maximum disk utilization for all screen shots.
  • An option to open a new Finder window, navigated to the folder where TimeSnapper saves its images.
  • Getting TimeSnapper to optionally start automatically after reboots. (This functionality on Mac was almost shockingly difficult to implement relative to what I expected, requiring quite a bit of code along with a whole "sub-application".) 
  • Getting TimeSnapper to appear as an icon and menu in the Mac's top Menu Bar, and to display its larger Dock icon only when one of its windows is open.
  • An initial "Play Your Day Like a Movie" window, displaying one of the saved screen shots.
  • Adding a timeline to the Play Your Day window, displaying a range of hours corresponding to the earliest and latest screenshot captured for a selected day, and a tick mark on the timeline for the time of every individual screenshot taken.
  • Getting a mouse click -- and later, drag -- on the timeline to change the image display to the image taken nearest to the clicked time.
  • Adding the eponymous ability for the window to play the selected day's screenshots like a movie, with playback controls for starting/pausing the playback and increasing or decreasing the playback speed.
  • Handling local time changes properly, so that "going back in time" by carrying the Mac across a time zone boundary from east to west, or at the end of Daylight Saving Time, doesn't cause screen shots to appear out-of-order in the Play Your Day window, or to potentially overwrite one another.
  • Lots more polish and bug squashing!
It's been a genuine pleasure over the past few months, in the later phases of development, to once again have had TimeSnapper running on my daily-use computer -- now, a Mac -- affording me the ability to easily peer back in time and see exactly what text or activity I previously had on my screen!

Check out TimeSnapper on the Mac App Store! If you like it, I'd love it if you'd leave a nice review, or just drop me a line (here in the comments, or find me on Twitter) and let me know what you think!