When Thunderbird's Quick Filter is initially summoned, it shows a text field, with buttons that are right justified to the window. When filtering criteria are met, such as simply clicking the "Show only unread messages" button, the message count appears to the right of the filter buttons, shifting them to the left. As a result, if a desktop user wants to toggle the "Show only unread messages" (or other) button on then off again, they must "chase" the button to its new location, which requires looking back for the new location of the button bar and moving the mouse. I would suggest the message count appear between the text box and the filter buttons, so that the filter buttons do not relocate. i.e. before application of a filter, the Quick Filter bar appears as: [Filter messages... <CTRL>+<SHIFT>+<K> ][icon][icon][icon][icon][icon] After application, it currently it appears as [Filter messages... <CTRL>+<SHIFT>+<K>][ICON][icon][icon][icon][icon] 15 messages whereas I suggest: [Filter messages... <CTRL>+<SHIFT>+<K>] 15 messages [ICON][icon][icon][icon][icon] So that the buttons (illustrated here as [icon] with [ICON] as the enabled filter), do not move upon application, and so the user may simply click the mouse button a second time to disable the filter just applied, without having to visually consult the button's new location and move the mouse pointer.
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