title: Delphi: Show/Hide Glyph from a TBitbtn
body: <p>I would like to hide or show the glyph from a <code>bitbtn</code> after the same button is pressed.</p>
  
  <p>Example: I have on a form with a 'Back' button and a 'Next' button. Both have a glyph with arrows. After the 'Next' button is pressed it's transforming in 'Finish' button without a glyph. Similar if the 'Back' button is pressed, the 'Finish' button is becoming 'Next' button with the arrow glyph. Finish button have no icon.</p>