For a title bar, you could use cursor hinting or a gripable texture as a pliancy hint.

例如，标题栏可以用亮度方面的轻微改变作为受范暗示，或者可以用光标暗示。

youdao

The soft texture of the bar saves the artifacts from breaking.

酒吧的质地较软的保存文物破。

youdao

The software isn't bad--in fact, you could argue it's the hot-selling Macintosh computer's secret weapon--but no one was gasping in awe as Schiller showed off the ability to add a stone texture to bar charts in Numbers, Apple's spreadsheet software.

FORBES: Macworld '09