Please document all known AT bugs in this document.
Contents
- The screen reader must be turned on and reading before the browser is open for it to work. See phetsims/a11y-research#90.
- The screen reader might focus the last user interface component that had focus on sim load, typically on refresh. This is a "feature". For example, see phetsims/resistance-in-a-wire#139.
- If the sim contains abbreviations (chemical formulas or other) the screen reader may try to read phonetically. We decided to accept this. See phetsims/molarity#215.
- Be aware that JAWS may shift keyboard focus with Firefox Quantum. See phetsims/balloons-and-static-electricity#404.
- If you use a slider by pressing and holding an arrow key, you will hear duplicate alerts that read the value when you release the arrow key. See phetsims/john-travoltage#227.
- If you quickly move through slider values with arrow keys and reach the end of the range, JAWS won’t read the final value and it will be silent, see phetsims/john-travoltage#246.
- When using a slider and holding down an arrow key, you might see the thumb move slowly while holding the key down, then move rapidly in one direction when you release a key, see phetsims/john-travoltage#242.
- JAWS might not automatically switch to forms mode for some controls (like sliders and radio buttons). In this case, pressing "enter" should switch to forms mode. See phetsims/resistance-in-a-wire#138.
- When using a slider, if value is at min/max and you press and hold an arrow key to try to move the value beyond the range, JAWS might crash. See phetsims/john-travoltage#242.
- When reading about a slider with the virtual cursor, JAWS might read the min/max value with floating point rounding errors. For example “0.1” might sound like “0.1000...01”. See phetsims/resistance-in-a-wire#177.
- If you click on the Windows taskbar (maybe other things too) pressing arrow keys will have no response from JAWS. Return to the browser and arrow keys should continue to work as expected.
- When focused on draggable objects, using the arrow keys will not move the object when JAWS is enabled because of phetsims/a11y-research#9. WASD keys should still work.
- If you use a slider by pressing and holding an arrow key, you will hear duplicate alerts that read the value when you release the arrow key. See phetsims/john-travoltage#227.
- When using a slider and holding down an arrow key, you might see the thumb move slowly while holding the key down, then move rapidly in one direction when you release a key, see phetsims/john-travoltage#242.
- If there is a list in a dialog, when the dialog is first opened JAWS will read the list items as "bullet, bullet, ..." instead of reading the names of the items. See phetsims/a11y-research#185.
- When changing screens from the Home Screen, NVDA may read the page title several times and then the first line in the new screen before the first item in the new screen. See phetsims/ratio-and-proportion#321
- When the values of sliders are read out sometimes NVDA will read out the wrong value. Adjusting those sliders seems to fix the issue. Likely an “AT caching” issue. phetsims/resistance-in-a-wire#202
- NVDA will read through the Sim Screen Overview when exiting a dialog
- NVDA may say name of WASD keys when pressed
- NVDA might get "stuck" on the heading of a dialog. You have to press "tab" to get out of it. See phetsims/quadrilateral#452
- Home/End/Page Up/Page Down from the number pad do not work with NVDA. See phetsims/sun#872.
- When using a ComboBox, the name of the ComboBox button can be incorrect after changing selection. See phetsims/a11y-research#196.
- NVDA may incorrectly describe components as "unavailable" after they are re-enabled. See phetsims/a11y-research#197.
- When closing a dialog with “escape” while the virtual cursor is on a list item, focus might not return to the Keyboard Help button in the navigation bar. See phetsims/ohms-law#114. A user setting fixes this.
- When using VoiceOver and the “Increment” feature on a slider (ctrl+option+spacebar), VoiceOver will sometimes read the previous aria-valuetext instead of the new one. See phetsims/a11y-research#36.
- VoiceOver doesn’t interrupt alerts as aggressively as some other AT, so older alerts might queue and be read one after the other.
- In iOS 14, VoiceOver has a setting to describe images, which is on by default, and it is really bad at doing it for PhET Sims! To turn off this setting (as of 1/19/21), Settings -> Accessibility -> VoiceOver -> Verbosity -> Scene Descriptions -> switch off. See phetsims/ratio-and-proportion#256 for more details.
- After a bit of use, VoiceOver may stop speaking alerts related to the slider value (aria-valuetext). Tabbing away from the component then returning to it will cause VoiceOver to speak its content again. See phetsims/sun#508 and phetsims/ohms-law#141
- When using a slider, "Home" and "End" keys will both change the value AND move the cursor to a different place in the document. See phetsims/a11y-research#164.
- When using a combo box, Safari may say "Text" after reading each item in the combo box list. See phetsims/greenhouse-effect#178.
- Safari will duplicate alerts when the sim is embedded in an iFrame. See phetsims/friction#286
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Sometimes when using VoiceOver, Safari buttons (like “reload” and “new tab” are not clickable by double tapping the screen. Restarting Safari fixes the problem.
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iOS VoiceOver may skip over dynamic content in the PDOM when reading with swipe gestures. See phetsims/a11y-research#175
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iOS VoiceOver reads radio buttons as "radio button, checkbox". See https://github.com/Nancy-Salpepi.
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iOS VoiceOver does not queue any context responses (aria-live), see phetsims/utterance-queue#117
- When using a slider, if End/Home is pressed at the same time as Home/End, the browser will treat the keypress just like an arrow key and the value won’t be set to max/min. See phetsims/resistance-in-a-wire#163.
- When moving sliders using the keyboard navigation, you can use shift and pg up and pg down to modify the speed of the sliders. However, shift can be pressed at any time during the slider’s motion to slow it. Conversely, the pg up and pg down keys can only be pressed at the start of the slider’s motion to affect it. This difference in behavior is normal.
- To get keyboard navigation to work properly in Firefox:
System Preferences -> Keyboard -> Shortcuts -> All controls.
- To get keyboard navigation to work properly in Safari:
Safari -> Preferences -> Advanced -> Press Tab to highlight each item on a webpage.
- For some of the non-default Voices, it takes some time to render the information and performance of the sim may be reduced. At this time this is acceptable and there is nothing we can do to improve this. Acceptable performance is subjective, in general please create an issue if there are any questions about performance.
- Voicing and SpeechSynthesis can be slower to start on ChromeOS. Especially when switching tabs or turning it on for the first time. If Voicing doesn't start for ~8 seconds after you enable it or play with the sim that is expected. If it takes longer to start or never starts that is probably an issue. See phetsims/number-play#138
- Changing voices on iOS Safari is broken. The control for selecting voices have been removed on this platform. See phetsims/utterance-queue#74.