My current distro is Linux Mint MATE Version 18.2 (Sonya). Recently, I noticed that I would minimize a running application (e.g. LibreOffice Writer), but no placeholder for the app showed up in the panel. Initially, I thought that there was a problem with the panel’s settings, i.e. the Window List option was not set. I turned this on (Panel – Right-click – Add – Window List) only to find that the placeholder still wasn’t being displayed. Then, I realized this only happened when the application was initially running on the second monitor of my dual-monitor setup. However, as usual, Linux is sufficiently flexible to accommodate my situation, although the process is not particularly intuitive.
The trick is to add a panel to the second monitor. However, at a first glance it appears that the only placement options for adding a panel are on the top, bottom and sides of the primary monitor. The (tortuous) way forward is as follows:
(1) Right-click on the (lower) panel on the primary monitor and select New Panel. A second panel will be displayed along the top edge of the primary monitor.
(2) Right-click on the new panel and select Properties. Uncheck the box labeled “Expand” and press “Close”. The top panel will shrink to a small bar in the top-centre of the primary monitor.
(3) Left-click on this short panel, hold down the mouse button, and drag the panel to the bottom edge of the second monitor.
(4) Right-click on the short panel, select Properties, check the box labeled “Expand”, and press “Close”. The new panel now expands across the entire lower edge of the second monitor.
(5) Right-click on this new panel and select “Add to Panel”. Scroll down the list, click on “Window List”, and press “Close”.
Now, when an application is active on the second monitor, its placeholder will be displayed on the panel on the second monitor. Finally, I can once again (easily) minimize and re-establish application windows on my second monitor’s screen.
[SOLVED] Minimize to taskbar not working?
taskbar on second monitor