Window Components

Window Operations

Secondary Windows

Controls

Menus

Toolbars & Status Bars

Property Sheets

Dialog Boxes

Message Boxes

Palette Windows

Popup Windows

 		The basic operations for a window include: activation and deactivation, opening and closing, moving, sizing, scrolling, and splitting. The following sections describe these operations.

Activating and Deactivating Windows:
While the system supports the display of multiple windows, the user generally works within a single window at a time. This window is called the active window. The active window is typically at the top of the window Z order. It is also visually distinguished by its title bar that is displayed in the active window title color. All other windows are inactive with respect to the user's input; that is, while other windows can have ongoing processes, only the active window receives the user's input. The title bar of an inactive window displays the system inactive window color. Your application can query the system for the current values for the active title bar color and the inactive title bar color.

The user activates a primary window by switching to it; this inactivates any other primary windows. To activate a window with the mouse or pen, the user clicks or taps on any part of the window, including its interior. If the window is minimized, the user clicks (taps) the button representing the window in the taskbar. From the keyboard, the system provides the ALT+TAB key combination for switching between primary windows. The SHIFT+ALT+TAB key also switches between windows, but in reverse order. (The system also supports ALT+ESC for switching between windows.) The reactivation of a window should not affect any pre-existing selection within it; the selection and focus are restored to the previously active state.

When the user reactivates a primary window, the window and all its secondary windows come to the top of the window order and maintain their relative positions. If the user activates a secondary window, its primary window comes to the top of the window order along with the primary window's other secondary windows.

When a window becomes inactive, hide the selection feedback (for example, display of highlighting or handles) of any selection within it to prevent confusion over which window is receiving keyboard input. A direct manipulation transfer (drag and drop) is an exception. Here, you can display transfer feedback if the pointer is over the window during the drag operation. Do not activate the window unless the user releases the mouse button (the pen tip is lifted) in that window.

Opening and Closing Windows:


When the user opens a primary window, include an entry for it on the taskbar. If the window has been opened previously, restore the window to its size and position when it was last closed. If possible and appropriate, reinstate the other related view information, such as selection state, scroll position, and type of view. When opening a primary window for the first time, open it to a reasonable default size and position as best defined by the object or application.

Because display resolution and orientation varies, your software should not assume a fixed display size, but rather adapt to the shape and size defined by the system. If you use standard system interfaces the system automatically places your windows relative to the current display configuration.

Opening the primary window activates that window and places it at the top of the window order. If the use attempts to open a primary window that is already open within the same desktop, activate the existing window using the following recommendations. If the existing window is minimized, restore it when you activate it.

File type

Action when repeating an Open operation

Document or data file

Activates the existing window of the object and displays it at the top of the window Z order.

Application file

Displays a message box indicating that an open window of that application already exists and offers the user the option to switch to the open window or to open another window. Either choice activates the selected window and brings it to the top of the window Z order.

Document file that is already open in an MDI application window

Activates the existing window of the file. Its MDI parent window comes to the top of the window Z order, and the file appears at the top of the Z order within its MDI parent window.

Document file that is not already open, but its associated MDI application is already running (open)

Opens a new instance of the file's associated MDI application at the top of the window Z order and displays the child window for the file. Optionally, as an alternative, displays a message box indicating that an open window of that application already exists and offers the user the option to use the existing window or to open a new parent window.


The user closes a primary window by clicking (for a pen, tapping the screen) the Close button in the title bar or choosing the Close command from the window's pop-up menu. Although the system supports double-clicking (with a pen, double-tapping the screen) on the title bar icon as a shortcut for closing the window for compatibility with previous versions of Windows, avoid documenting this as the primary way to close a primary window. Instead, document the Close button.

When the user chooses the Close command, if your application does not automatically save these changes and pending transactions or edits that have not yet been saved to file remain, display a message asking the user whether to save any changes, discard any changes, or cancel the Close operation before closing the window. If there are no pending transactions, just close the window. Follow this same convention for any other command that results in closing the primary window (for example, Exit or Shut Down).

When closing the primary window, close any of its dependent secondary windows as well. The design of your application determines whether closing the primary window also ends the application processes. For example, closing the window of a text document typically halts any application code or processes remaining for inputting or formatting text. However, closing the window of a printer has no effect on the jobs in the printer's queue. In both cases, closing the window removes its entry from the taskbar.



Moving Windows:


The user can move a window either by dragging its title bar using the mouse or pen or by using the Move command on the window's pop-up menu. On most configurations, an outline representation moves with the pointer during the operation, and the window is redisplayed in the new location after the completion of the move. (The system also provides a display property setting that redraws the window dynamically as it is moved.) After choosing the Move command, the user can move the window with the keyboard interface by using arrow keys and pressing the ENTER key to end the operation and establish the window's new location. Never allow the user to reposition a window so that it cannot be accessed.

A window need not be active before the user can move it. The action of moving the window implicitly activates it.

Moving a window may clip or reveal information shown in the window. In addition, activation can affect the view state of the window - for example, the current selection can be displayed. However, when the user moves a window, avoid making any changes to the content being viewed in that window.

Resizing Windows:


Make your primary windows resizable unless the information displayed in the window is fixed, such as in the Windows Calculator program. The system provides several conventions that support user resizing of a window.

Sizing Borders:


The user resizes a primary window by dragging the sizing border with the mouse or pen at the edge of a window or by using the Size command on the window's menu. An outline representation of the window moves with the pointer. (On some configurations, the system may include a display option to dynamically redraw the window as it is sized.) After completing the size operation, the window assumes its new size. Using the keyboard, the user can size the window by choosing the Size command, using the arrow keys, and pressing the ENTER key.

A window does not need to be active before the user can resize it. The action of sizing the window implicitly makes it active, and it remains active after the sizing operation.

When the user resizes a window to be smaller, you must determine how to display the information viewed in that window. Use the context and type of information to help you choose your approach. The most common approach is to clip the information. However, in other situations where you want the user to see as much information as possible, you may want to consider using different methods, such as rewrapping or scaling the information. Use these variations carefully because they may not be consistent with the resizing behavior of most windows. In addition, avoid these methods when readability or maintaining the structural relationship of the information is important.

Although the size of a primary window can vary, based on the user's preference, you can define a window's maximum size. When defining this size, consider the reasonable usage within the window, and the size and orientation of the screen.

Maximizing Windows:


Although the user may be able to directly resize a window to its maximum size, the Maximize command optimizes this operation. Include this command on a window's pop-up menu, and as the Maximize command button in the title bar of the window.

Maximizing a window increases the size of the window to its largest, optimum size. The system default setting for the maximum size is as large as the display, excluding the space used by the taskbar (or other application-defined desktop toolbars). For an MDI child window, the default maximize size fills the parent window. But, you can define the size to be less or, in some cases, more than the default dimensions.

When the user maximizes a window, replace the Maximize button with a Restore button. Then, disable the Maximize command and enable the Restore command on the pop-up menu for the window.

Minimizing Windows:


Minimizing a window reduces it to its smallest size. To support this command, include it on the pop-up menu for the window and as the Minimize command button in the title bar of the window.

For primary windows, minimizing removes the window from the screen, but leaves its entry in the taskbar. For MDI child windows, the window resizes to a minimum size within its parent window. To minimize a window, the user chooses the Minimize command from the window's pop-up menu or the Minimize command button on the title bar.

When the user minimizes a window, disable the Minimize command on the pop-up menu and enable the Restore command.

Restoring Windows:


Support the Restore command to restore a window to its previous size and position after the user has maximized or minimized the window. For maximized windows, enable this command on the window's pop-up menu and replace the Maximize button with the Restore button in the title bar of the window.

For minimized windows, also enable the Restore command in the pop-up menu of the window. The user restores a minimized primary window to its former size and position by clicking (for pens, tapping the screen) on its button in the taskbar that represents the window, selecting the Restore command on the pop-up menu of the window's taskbar button, or using the ALT+TAB (or the SHIFT+ALT+TAB) key combination.

Size Grip:


When you define a sizable window, you may include a size grip. A size grip is a special handle for sizing a window. It is not exclusive to the sizing border. To size the window, the user drags the grip and the window resizes following the same conventions as the sizing border.

Always locate the size grip in the lower right corner of the window. Typically, this means you place the size grip at the right end of a horizontal scroll bar or the bottom of a vertical scroll bar. However, if you include a status bar in the window, display the size grip at the far corner of the status bar instead. Never display the size grip in both locations at the same.

Scrolling Windows:


When the information viewed in a window exceeds the size of that window, the window should support scrolling. Scrolling enables the user to view portions of the object that are not currently visible in a window. Scrolling is commonly supported through the use of a scroll bar. A scroll bar is a rectangular control consisting of scroll arrows, a scroll box, and a scroll bar shaft.

Scroll bar and its components:

You can include a vertical scroll bar, a horizontal scroll bar, or both. Align a scroll bar with the vertical or horizontal edge of the window orientation it supports. If the content is never scrollable in a particular direction, do not include a scroll bar for that direction.

The common practice is to display scroll bars if the view requires some scrolling under any circumstances. If the window becomes inactive or resized so that its content does not require scrolling, you should continue to display the scroll bars. While removing the scroll bars when the window is inactive potentially allows the display of more information and feedback about the state of the window, it also requires the user to explicitly activate the window to scroll. Consistently displaying scroll bars provides a more stable environment.

Scroll Arrows:


Scroll arrow buttons appear at each end of a scroll bar, pointing in opposite directions away from the center of the scroll bar. The scroll arrows point in the direction that the window "moves" over the data. When the user clicks (for pens, tapping the screen) a scroll arrow, the data in the window moves, revealing information in the direction of the arrow in appropriate increments. The granularity of the increment depends on the nature of the content and context, but it is typically based on the size of a standard element. For example, you can use one line of text for vertical scrolling, one row for spreadsheets. You can also use an increment based a fixed unit of measure. Whichever convention you choose, maintain the same scrolling increment throughout a window. The objective is to provide an increment that provides smooth but efficient scrolling. When a window cannot be scrolled any further in a particular direction, disable the scroll arrow corresponding to that direction.

When scroll arrow buttons are pressed and held, they exhibit a special auto-repeat behavior. This action causes the window to continue scrolling in the associated direction as long as the pointer remains over the arrow button. If the pointer is moved off the arrow button while the user presses the mouse button, the auto-repeat behavior stops and does not continue unless the pointer is moved back over the arrow button (also when the pen tip is moved off the control).

Scroll Box:


The scroll box, sometimes referred to as the elevator, thumb, or slider, moves along the scroll bar to indicate how far the visible portion is from the top (for vertical scroll bars) or from the left edge (for horizontal scroll bars). For example, if the current view is in the middle of a document, the scroll box in the vertical scroll bar is displayed in the middle of the scroll bar.

The size of the scroll box can vary to reflect the difference between what is visible in the window and the entire content of the file.


Proportional relationship between scroll box and content:

For example, if the content of the entire document is visible in a window, the scroll box extends the entire length of the scroll bar, and the scroll arrows are disabled. Make the minimum size of the scroll box no smaller than the width of a window's sizing border.

The user can also scroll a window by dragging the scroll box. Update the view continuously as the user moves the scroll box. If you cannot support scrolling at a reasonable speed, you can scroll the information at the end of the drag operation as an alternative.

If the user starts dragging the scroll box and then moves the pointer outside of the scroll bar, the scroll box returns to its original position. The distance the user can move the pointer off the scroll bar before the scroll box snaps back to its original position is proportional to the width of the scroll bar. If dragging ends at this point, the scroll action is canceled - that is, no scrolling occurs. However, if the user moves the pointer back within the scroll-sensitive area, the scroll box returns to tracking the pointer movement. This behavior allows the user to scroll without having to remain within the scroll bar and to selectively cancel the initiation of a drag-scroll operation.

Dragging the scroll box to the end of the scroll bar implies scrolling to the end of that dimension; this does not always mean that the area cannot be scrolled further. If your application's document structure extends beyond the data itself, you can interpret dragging the scroll box to the end of its scroll bar as moving to the end of the data rather than the end of the structure. For example, a typical spreadsheet exceeds the data in it - that is, the spreadsheet may have 65,000 rows, with data only in the first 50 rows. This means you can implement the scroll bar so that dragging the scroll box to the bottom of the vertical scroll bar scrolls to the last row containing data rather than the last row of the spreadsheet. The user can use the scroll arrow buttons to scroll further to the end of the structure. This situation also illustrates why disabling the scroll arrow buttons can provide important feedback so that the user can distinguish between scrolling to the end of data from scrolling to the end of the extent or structure. In the example of the spreadsheet, when the user drags the scroll box to the end of the scroll bar, the arrow would still be shown as enabled because the user can still scroll further, but it would be disabled when the user scrolls to the end of the spreadsheet.

Scroll Bar Shaft:


The scroll bar shaft not only provides a visual context for the scroll box, it also serves as part of the scrolling interface. Clicking in the scroll bar shaft should scroll the view an equivalent size of the visible area in the direction of the click. For example, if the user clicks in the shaft below the scroll box in a vertical scroll bar, scroll the view a distance equivalent to the height of the view. Where possible, allow overlap from the previous view. For example, if the user clicks below the scroll box, the bottom line becomes the top line of scrolled view. The same thing applies for clicking above the scroll box and horizontal scrolling. These conventions provide the user with a common reference point.

Scrolling with the scroll bar shaft by a screenful

Pressing and holding mouse button 1 with the pointer in the shaft auto-repeats the scrolling action. If the user moves the pointer outside the scroll-sensitive area while pressing the button, the scrolling action stops. The user can resume scrolling by moving the pointer back into the scroll bar area. (This behavior is similar to the effect of dragging the scroll box.)

Automatic Scrolling


The techniques previously summarized describe the explicit ways for scrolling. However, the user can also scroll as a secondary result of another user action. This type of scrolling is called automatic scrolling. The situations in which to support automatic scrolling are as follows:
When the user begins or adjusts a selection and drags it past the edge of the scroll bar or window, scroll the area in the direction of the drag.
When the user drags an object and approaches the edge of a scrollable area, scroll the area following the recommended auto-scroll conventions covered in Chapter 5, "General Interaction Techniques." Base the scrolling increment on the context of the destination and, if appropriate, on the size of the object being dragged.
When the user enters text from the keyboard at the edge of a window or moves or copies an object into a location at the edge of a window, the view should scroll to allow the user to focus on the inserted information. The amount to scroll depends on context. For example, for text, vertically scroll a single line at a time. When scrolling horizontally, scroll in units greater than a single character to prevent continuous or uneven scrolling. Similarly, when the user transfers a graphic object near the edge of the view, base scrolling on the size of the object.
If an operation results in a selection or moves the cursor, scroll the view to display the new selection. For example, for a Find command that selects a matching object, scroll the object into view because usually the user wants to focus on that location. In addition, other forms of navigation may cause scrolling. For example, completing an entry field in a form may result in navigating to the next field. In this case, if the field is not visible, the form can scroll to display it.



Keyboard Scrolling:


Use navigation keys to support scrolling with the keyboard. When the user presses a navigation key, the cursor moves to the appropriate location. For example, in addition to moving the cursor, pressing arrow keys at the edge of a scrollable area scrolls in the corresponding direction. Similarly, the PAGE UP and PAGE DOWN keys are comparable to clicking in the scroll bar shaft, but they also move the cursor.

Optionally, you can use the SCROLL LOCK key to facilitate keyboard scrolling. In this case, when the SCROLL LOCK key is toggled on and the user presses a navigation key, scroll the view without affecting the cursor or selection.

Placing Adjacent Controls:


It is sometimes convenient to locate controls or status bars adjacent to a scroll bar and position the end of the scroll bar to accommodate them. Take care when placing adjacent elements; too many can make it difficult for users to scroll, particularly if you reduce the scroll bar too much. If you need a large number of controls, consider using a conventional toolbar instead.

Note
For more information about toolbars, see Toolbars.

Splitting Windows:


A window can be split into two or more separate viewing areas, which are called panes. For example, a split window allows the user to examine two parts of a document at the same time. You can also use a split window to display different, yet simultaneous, views of the same information.

While you can use a split window pane to view the contents of multiple files or containers at the same time, displaying these in separate windows typically allows the user to better identify the files as individual elements. When you need to present views of multiple files as a single task, consider window management techniques, such as MDI.

The panes that appear in a split window can be implemented either as part of a window's basic design or as a user-configurable option. To support splitting a window that is not presplit by design, include a split box. A split box is a special control placed adjacent to the end of a scroll bar that splits or adjusts the split of a window. The size of the split box should be just large enough for the user to successfully target it with the pointer; the default size of a size handle, such as the window's sizing border, is a good guideline. Locate the split box at the top of the up arrow button of the vertical scroll bar.

The user splits a window by dragging the split box to the desired position. When the user positions the hot spot of the pointer over a split box, change the pointer's image to provide feedback and help the user target the split box. While the user drags the split box, move a representation of the split box and split bar with the pointer.

At the end of the drag, display a visual separator, called the split bar, that extends from one side of the window to the other, defining the edge between the resulting panes, as shown in Figure 6.12. Base the size for the split bar to be, at a minimum, the current setting for the size of window sizing borders. This allows you to appropriately adjust when a user adjusts size borders. If you display the split box after the split operation, place it adjacent to the split bar.

You can support dragging the split bar (or split box) to the end of the scroll bar to close the split. Optionally, you can also support double-clicking (or, for pens, double-tapping) as a shortcut technique for splitting the window at some default location (for example, in the middle of the window or at the last split location) or for removing the split. This technique works best when the resulting window panes display peer views. It may not be appropriate when the design of the window requires that it always be displayed as split or for some types of specialized views.

To provide a keyboard interface for splitting the window, include a Split command on the window or view's menu. When the user chooses the Split command, split the window in the middle or in a context-defined location. Support arrow keys for moving the split box up or down; pressing the ENTER key sets the split at the current location. Pressing the ESC key cancels the split mode.

You can also use other commands to create a split window. For example, you can define specialized views that, when selected by the user, split a window to a fixed or variable set of panes. Similarly, you can enable the user to remove the split of a window by closing a view pane or by selecting another view command.

When the user splits a window, add scroll bars if the resulting panes require scrolling. In addition, you may need to scroll the information in panes so that the split bar does not obscure the content over which it appears. Use a single scroll bar, at the appropriate side of the window, for a set of panes that scroll together. However, if the panes each require independent scrolling, a scroll bar should appear in each pane for that purpose. For example, the vertical scroll bars of a set of panes in a horizontally split window are typically controlled separately.

When you use split window panes to provide separate views, independently maintain each pane's view properties, such as view type and selection state. Display only the selection in the active pane. However, if the selection state is shared across the panes, display a selection in all panes and support selection adjustment across panes.

When a window is closed, save the window's split state (that is, the number of splits, the place where they appear, the scrolled position in each split, and its selection state) as part of the view state information for that window so that it can be restored the next time the window is opened.


The Windows Interface Guidline for Software Design (p.119)