Bug 97918 [formatter] tab policy and indentation policy: indent on column
I would like a smarter tab policy. In code formated like this: class Example { Example(int arg1, int arg2, int arg3, int arg4, int arg5, int arg6) { this(); } Example() { } } I would like to have a mix of tabs and spaces like this: class Example { <tb>Example(int arg1, int arg2, <tb> int arg3, int arg4, <tb> int arg5, int arg6) { <tb><tb>this(); <tb>} <tb>Example() { <tb>} } If the code it is formated like this then it looks good whether a editor is using 4 or 8 space tabs. I called this a smarter tab policy because it means the code that implements the tab policy needs to know more than just a column number. It needs an indentation level and column offset. This could be configured by setting the tab policy to "mixed" and then have a check box that says "use spaces for column alignment" Or it could be configured by a new tab policy called "portable mixed", and in that case only the tab size field is needed. On another note it is bad that the Constructor Declarations->parameters example in the code formatting dialog uses the word "Example" which happens to be 8 chars. So in "tab only" tab policy with tabs of 2,4, or 8, the example doesn't show what will happen when "indent on column" is set. The method declarations->parameters example makes this clear.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/preferences/formatter/IndentationTabPage.java
fPreview.setPreviewText(PREVIEW);
	}
	
    /* (non-Javadoc)
     * @see org.eclipse.jdt.internal.ui.preferences.formatter.ModifyDialogTabPage#doCreateJavaPreview(org.eclipse.swt.widgets.Composite)
     */
    protected JavaPreview doCreateJavaPreview(Composite parent) {
        fPreview= new CompilationUnitPreview(fWorkingValues, parent);
        return fPreview;
    }
    /* (non-Javadoc)
     * @see org.eclipse.jdt.internal.ui.preferences.formatter.ModifyDialogTabPage#doUpdatePreview()
     */
    protected void doUpdatePreview() {
        fPreview.update();
    }
	private void updateTabPreferences(String tabPolicy, NumberPreference tabPreference, NumberPreference indentPreference) {
		/*
		 * If the tab-char is SPACE (or TAB), INDENTATION_SIZE
		 * preference is not used by the core formatter. We piggy back the
		 * visual tab length setting in that preference in that case. If the
		 * user selects MIXED, we use the previous TAB_SIZE preference as the
		 * new INDENTATION_SIZE (as this is what it really is) and set the 
		 * visual tab size to the value piggy backed in the INDENTATION_SIZE
		 * preference. See also CodeFormatterUtil. 
		 */
		if (DefaultCodeFormatterConstants.MIXED.equals(tabPolicy)) {
			if (JavaCore.SPACE.equals(fOldTabChar) || JavaCore.TAB.equals(fOldTabChar))
				swapTabValues();
			tabPreference.setEnabled(true);