Language, text size and text that does not fit

The Audit view finding a label that is too long for its line

Text is where layouts break: a German word is longer, Arabic runs right to left, a person who needs big text sets it to 200%. EmuLabZip can change the language and text size of a device, check the screen for text that does not fit, and sweep a screen across several languages and sizes in one command.

Changing the device#

emulabzip control locale en-XA --app com.example.shop   # long, accented text
emulabzip control locale ar-XB --app com.example.shop   # right to left
emulabzip control reset-locale --app com.example.shop
emulabzip control font-scale 130                        # percent of normal; 100 puts it back
emulabzip control display --width 720 --height 1600 --density 320     # Android
emulabzip control reset-display

	Android	iOS Simulator
Language	`cmd locale set-app-locales`: one app at a time, Android 13 and newer. The pseudo-locales `en-XA` and `ar-XB` work. The app is told and recreates its screen	`defaults write -g AppleLanguages` and `AppleLocale` for the whole simulator; an app picks it up when it starts again
Text size	`settings put system font_scale`	`simctl ui … content_size`: the Dynamic Type size nearest the percentage (130% is `extra-extra-extra-large`, 200% `accessibility-extra-large`)
Display size and density	`wm size`, `wm density`	Not available

A language tag is letters, digits and hyphens (de-DE, pt-BR, zh-Hans-CN). Text size is 50 to 300 percent. All of these are in the Controls view too, under Text size and language and Display size.

Checking a screen#

emulabzip i18n check            # the screen as it is now
emulabzip i18n check --rtl      # it is shown in a right-to-left language: also check the layout was mirrored

Rule	Looks for
`text-off-screen`	Text that reaches past the edge of the screen (unless it is in something that scrolls)
`text-clipped-by-parent`	Text that does not fit inside its container, so the container cuts it
`text-cut-off`	A single line of text held to the room it was given, whose ink reaches the end of its box: it is probably cut off or ends in an ellipsis
`rtl-not-mirrored`	In a right-to-left language, most of the screen's text still on the left

text-cut-off is a heuristic. The layout says where each view is, and the screenshot says whether its text runs to the end of the box. A label that merely hugs its text is not reported (its box is only as wide as the text), and a label is only reported when its box ends where its container, or the next view in its row, leaves no room. The message says "may be". Without a screenshot only the layout rules run.

Sweeping#

emulabzip i18n sweep --app com.example.shop --locales en-XA,ar-XB --scales 100,130,200

The sweep tries each language at each text size, reads the layout, and prints a table: how many findings, which, and which are worse than the device as it is now. The device is put back (text size and language) when it finishes, and also when a step fails. --fail-on-worse exits with 1 when any setting is worse. On the iOS Simulator only text sizes are swept, because an app only takes a new language when it starts again.

Text scaling is also looked at through the sweep: at 200% it reports touch targets and focus order that got worse.

For assistants#

Over MCP: control_locale, control_font_scale, control_display_size and check_text.

Limits#

Android changes the language of an app, not the device. Device-wide languages need root.
The heuristics see views, not glyphs. An icon font, a custom-drawn label or text in a game is not judged.
Pseudo-locales rely on the app having its strings in resources; hard-coded text stays as it is.