cca@pur-phy (Charles C. Allen) (03/12/88)
Random personal opinions follow... Some people have mentioned using modifier keys along with the mouse button for calling up menus. I hope this never makes it into the Apple Human Interface Guidelines (AHIG). The AHIG always use the mouse button as a selection button. Using modifier keys should "modify" the selection (shift-click selects multiple, etc.). I find using a modifer/button combo for something other than a selection modification confusing. Trapeze uses option-click to resize and command-click to move a block (or is it the other way around?). Each button on a mouse should have a purpose orthogonal to the other buttons. In Smalltalk, the left button selects, the middle button brings up a menu for "what's under the cursor", and the right button brings up a menu for the view (window) as a whole. In the Apple version, there are two ways to simulate the middle and right buttons. The middle button menu can be reached by command-click, or by moving the mouse to an area of the scroll bar (the cursor changes shape when the menu is available). The right button menu can be reached by enter-click (I think), or by clicking in the title tab of the view. I always use the second alternative in each case, partly because the first alternatives require driving the mouse with two hands, partly because the first alternatives mean using "the" button for something other than selection. Popup palettes and menus can be useful, but only if clicking on them doesn't produce a "destructive" effect. This usually means making sure the current selection is under the cursor when the palette/menu pops up. I'll pick on Trapeze again for violating this. All the popup menus in Trapeze put the menu head at the location of the mouse click. If you accidentally click in the menu location (instead of holding the button down), you end up changing the selection to whatever is at the top of the list. [I don't have the AHIG with me. Out of curiousity, does it mention anything about this? I don't recall...]. A rule of thumb I use is that I like to be able to explore an application using just the mouse, without the keyboard (so I can have a mug of tea in my other hand :-). Text entry is unique, obviously. Entering integers in a dialog text box? Bleah. As long as the range is limited, why not put in some sort of control (perhaps as an alternate). The above are just some semi-random thoughts on my personal preferences, along with some explanation for why I like things that way. If you disagree, why, that's great. Charlie Allen cca@newton.physics.purdue.edu