Auto-selected text in a browser address bar

A changable setting in Firefox governs text selection in the address bar.

Type about:config in the Firefox address bar, search for browser.urlbar.clickSelectsAll and change its value to true by double clicking.

You may also want to use ctrl+l or alt+d to autoselect text in the address bar, and ctrl+k to do the same in the search bar.

On my system, when I press F6 the contents of the address bar in Firefox are selected, just as you wish. The same behaviour with Iron (a derivate of Google Chrome).

To select the text (if any) on the search bar on Firefox, then you can press F6 and then Tab.

About the "black text area" I don't know; maybe you mean "blank text area", meaning that once you start typing, the (selected) text is substituted?

In Opera, you press F2 to open a window where you can type a new URI.

For searches, I have configured several search keywords in Opera's integrated search, so I simply press F2 and type, for example, d recipe, to search for the word "recipe" on DuckDuckGo.com or doi 10.1126/science.1100199 to go to this paper.

Firefox

On the address bar write about:config and press enter.

Press the I'll be careful warning

On the search bar look for browser.urlbar.clickSelectsAll and change the value to true.