My instances are intended to be components in a structured picture. Each View in the structured picture can contain other Views as sub-components. These sub-components are called subViews. A View can be a subView of only one View. This View is called its superView. The set of Views in a structured picture forms a hierarchy. The one View in the hierarchy that has no superView is called the topView of the structured picture. A View in a structured picture with no subViews is called a bottom View. A View and all of its subViews, and all of their subViews and so on, are treated as a unit in many operations on the View. For example, if a View is displayed, all of its subViews are displayed as well. There are several categories of operations that can be performed on a View. Among these are the following:

1. Adding subViews to a View.
2. Positioning subViews within a View.
3. Deleting subViews from a View.
4. Transforming a View.
5. Displaying a View.

Each View has its own coordinate system. In order to change from one coordinate system to another, each View has two transformations associated with it. The local transformation is a WindowingTransformation that maps objects in the coordinate system of the View to objects in the coordinate system of the superView of the View. The displayTransformation is a WindowingTransformation that maps objects in the coordinate system of the View to objects in the display screen coordinate system.

The part of the space that is to be made visible is represented by the window of the View. The window of a View is a Rectangle expressed in the coordinate system of the View. The area occupied by a View in the coordinate system of its superView is called its viewport. The viewport of a View is its window transformed by its local transformation. The region of the display screen occupied by a View is called its displayBox. The display box of a View can include a border. The width of the border expressed in display screen coordinates is called the border width of the View. The color of the border is called the border color. The region of the display box of a View excluding the border is called the inset display box. The color of the inset display box is called the inside color of the View.

	bordering
	backgroundColor backgroundColor: borderWidth borderWidth: borderWidthLeft:right:top:bottom: foregroundColor foregroundColor: insideColor:

	clearing
	clear clear: clearInside clearInside:

	controller access
	controller controller: defaultController defaultControllerClass model:controller:

	deEmphasizing
	deEmphasize deEmphasizeForDebugger deEmphasizeSubViews deEmphasizeView emphasize emphasizeSubViews emphasizeView

	display box access
	apparentDisplayBox boundingBox computeBoundingBox displayBox insetDisplayBox

	display transformation
	displayTransform: displayTransformation inverseDisplayTransform:

	displaying
	clippingTo:do: display displayBorder displayClippingTo: displayDeEmphasized displaySubViews displayView displayViewDeEmphasized inspectFirstSubView inspectModel inspectView maximumSize minimumSize

	indicating
	flash highlight

	initialize-release
	initialize release setDefaultBackgroundColor

	lock access
	isLocked isUnlocked lock unlock

	miscellaneous
	clipRect clipRect: gridSpacing nestedViewport printViewSpecOn:nested: stretchFrame:startingWith:

	model access
	model model:

	morphic compatibility
	setBalloonText:

	private
	computeDisplayTransformation computeInsetDisplayBox getController getViewport getWindow isCyclic: setTransformation: setWindow: superView:

	scrolling
	scrollBy:

	subView access
	firstSubView lastSubView resetSubViews subViewContaining: subViewSatisfying: subViews textEditorView

	subView inserting
	addSubView: addSubView:above: addSubView:align:with: addSubView:below: addSubView:ifCyclic: addSubView:toLeftOf: addSubView:toRightOf: addSubView:viewport: addSubView:window:viewport:

	subView removing
	releaseSubView: releaseSubViews removeFromSuperView removeSubView: removeSubViews

	superView access
	isTopView superView topView

	testing
	canDiscardEdits containsPoint: hasUnacceptedEdits isObscured

	transforming
	align:with: scale:translation: scaleBy: transform: transformation transformation: translateBy: window:viewport:

	updating
	update update:

	viewport access
	viewport

	window access
	defaultWindow insetWindow window window:

	basic control sequence	top
	subViewWantingControl Answer the first subView that has a controller that now wants control.

	bordering	top
	backgroundColor
	backgroundColor:
	borderWidth Answer either 0, indicating no border, or a Rectangle whose left value is the width in display coordinates of the receiver's left border. Right, top, and bottom widths are analogous. The border width is initially 0. A View with a border width of 0 will not have any border displayed.
	borderWidth: Set the four border widths of the receiver to anInteger.
	borderWidthLeft:right:top:bottom: Set the border widths of the receiver. These arguments represent the left, right, top, and bottom border widths.
	foregroundColor
	foregroundColor:
	insideColor:

	clearing	top
	clear Use the border color to paint the display box (including the border, see View|displayBox) of the receiver.
	clear: Use aColor to paint the display box (including the border, see View|displayBox) of the receiver.
	clearInside Use the inside color to paint the inset display box (excluding the border, see View|insetDisplayBox) of the receiver.
	clearInside: Use aColor to paint the inset display box (excluding the border, see View|insetDisplayBox) of the receiver.

	controller access	top
	controller If the receiver's controller is nil (the default case), answer an initialized instance of the receiver's default controller. If the receiver does not allow a controller, answer the symbol #NoControllerAllowed.
	controller: Set the receiver's controller to aController. #NoControllerAllowed can be specified to indicate that the receiver will not have a controller. The model of aController is set to the receiver's model.
	defaultController Answer an initialized instance of the receiver's default controller. Subclasses should redefine this message only if the default controller instances need to be initialized in a nonstandard way.
	defaultControllerClass Answer the class of the default controller for the receiver. Subclasses should redefine View|defaultControllerClass if the class of the default controller is not Controller.
	model:controller: Set the receiver's model to aModel, add the receiver to aModel's list of dependents, and set the receiver's controller to aController. Subsequent changes to aModel (see Model|change) will result in View|update: messages being sent to the receiver. #NoControllerAllowed for the value of aController indicates that no default controller is available; nil for the value of aController indicates that the default controller is to be used when needed. If aController is neither #NoControllerAllowed nor nil, its view is set to the receiver and its model is set to aModel.

	deEmphasizing	top
	deEmphasize Modify the emphasis (highlighting, special tabs) of the receiver. This includes objects such as labels, lines, and boxes. Typically used so that the receiver is not presented as active. Do this for the receiver and then for each of the receiver's subViews.
	deEmphasizeForDebugger Overridden by StandardSystemView. This default behavior does nothing.
	deEmphasizeSubViews Send the deEmphasize message to each of the receiver's subviews.
	deEmphasizeView Subclasses should redefine View|deEmphasizeView in order to modify the emphasis (highlighting, special tabs) of particular objects associated with the View such as labels, lines, and boxes.
	emphasize Modify the emphasis (highlighting, special tabs) of the receiver. This includes objects such as labels, lines, and boxes. Typically used so that the receiver is presented as active. Do this for the receiver and then for each of the receiver's subViews.
	emphasizeSubViews Send the emphasize message to each of the receiver's subviews.
	emphasizeView Subclasses should redefine View|emphasizeView in order to modify the emphasis (highlighting, special tabs) of particular objects associated with the View such as labels, lines, and boxes.

	display box access	top
	apparentDisplayBox
	boundingBox Answer the bounding box which for the default case is the rectangular area surrounding the bounding boxes of all the subViews.
	computeBoundingBox Answer the minimum Rectangle that encloses the bounding boxes of the receiver's subViews. If the receiver has no subViews, then the bounding box is the receiver's window. Subclasses should redefine View|boundingBox if a more suitable default for the case of no subViews is available.
	displayBox Answer the receiver's inset display box (see View|insetDisplayBox) expanded by the borderWidth. The display box represents the region of the display screen in which the receiver (including the border) is displayed. If the receiver is totally clipped by the display screen and its superView, the resulting Rectangle will be invalid.
	insetDisplayBox Answer the receiver's inset display box. The inset display box is the intersection of the receiver's window, tranformed to display coordinates, and the inset display box of the superView, inset by the border width. The inset display box represents the region of the display screen in which the inside of the receiver (all except the border) is displayed. If the receiver is totally clipped by the display screen and its superView, the resulting Rectangle will be invalid.

	display transformation	top
	displayTransform: Apply the display transformation of the receiver to anObject (see View|displayTransformation) and answer the resulting scaled, translated object. It is normally applied to Rectangles, Points, and other objects with coordinates defined in the View's local coordinate system in order to get a corresponding object in display coordinates.
	displayTransformation Answer a WindowingTransformation that is the result of composing all local transformations in the receiver's superView chain with the receiver's own local transformation. The resulting transformation transforms objects in the receiver's coordinate system into objects in the display screen coordinate system.
	inverseDisplayTransform: Answer a Point that is obtained from the argument, aPoint, by applying to it the inverse of the receiver's display transformation. It is typically used by the Controller of the receiver in order to convert a point in display coordinates, such as the cursor point, to the local coordinate system of the receiver.

	displaying	top
	clippingTo:do:
	display Display the receiver's border, display the receiver, then display the subViews of the receiver. Can be sent to the top View of a structured picture in order to display the entire structure, or to any particular View in the structure in order to display that View and its subViews. It is typically sent in response to an update request to a View.
	displayBorder Display the receiver's border (using the receiver's borderColor).
	displayClippingTo:
	displayDeEmphasized
	displaySubViews Display all the subViews of the receiver.
	displayView Subclasses should redefine View|displayView in order to display particular objects associated with the View such as labels, lines, and boxes.
	displayViewDeEmphasized
	inspectFirstSubView
	inspectModel
	inspectView
	maximumSize Answer the maximum size of the receiver.
	minimumSize Answer the minimum size of the receiver.

	indicating	top
	flash Cause the inset display box (the display box excluding the border, see View|insetDisplayBox) of the receiver to complement twice in succession.
	highlight Cause the inset display box (the display box excluding the border, see View|insetDisplayBox) of the receiver to complement.

	initialize-release	top
	initialize Initialize the state of the receiver. Subclasses should include 'super initialize' when redefining this message to insure proper initialization.
	release Remove the receiver from its model's list of dependents (if the model exists), and release all of its subViews. It is used to break possible cycles in the receiver and should be sent when the receiver is no longer needed. Subclasses should include 'super release.' when redefining release.
	setDefaultBackgroundColor Obtain the background color from the receiver's model, unless the #uniformWindowColors preference is set to true, in which case obtain it from generic Object; and install it as the receiver's background color. 5/1/96 sw

	lock access	top
	isLocked Answer whether the receiver is locked. A View is 'locked' if its display transformation and inset display box are defined. If these are undefined, the View is 'unlocked'. The display transformation and inset display box become undefined when the transformation of the View (or the transformation of a View in its superView chain) is changed, or when the superView of the View is changed, or any other change to the View that affects the display screen coordinates of the View. The locking and unlocking of a View is handled automatically by the internal methods of the View, but can also be done explicitly if desired (see View|lock, and View|unlock).
	isUnlocked Answer whether the receiver is unlocked. See comment in View|isLocked.
	lock 'Lock' the receiver and all of its subViews (see View|isLocked). This has the effect of computing and storing the display transformation (see View|displayTransformation) and inset display box (see View|insetDisplayBox) of the receiver and all its subViews. The locking and unlocking of a View is handled automatically by the internal methods of the View, but can also be done explicitly if desired.
	unlock Unlock the receiver and all of its subViews (see View|isUnlocked). This has the effect of forcing the display transformation (see View|displayTransformation) and inset display box (see View|insetDisplayBox) of the receiver and all its subViews to be recomputed the next time they are referenced. The locking and unlocking of a View is handled automatically by the internal methods of the View, but can also be done explicitly if desired.

	miscellaneous	top
	clipRect
	clipRect:
	gridSpacing
	nestedViewport The viewport size used to control scaling of nested user views.
	printViewSpecOn:nested: Print window and viewport specs of this and all nested views.
	stretchFrame:startingWith: Track the outline of a newFrame as long as mouse drags it. Maintain max and min constraints throughout the drag

	model access	top
	model Answer the receiver's model.
	model: Set the receiver's model to aModel. The model of the receiver's controller is also set to aModel.

	morphic compatibility	top
	setBalloonText: Unfortunately we just ignore this help text because we are not morphic

	private	top
	computeDisplayTransformation Answer a WindowingTransformation that transforms the coordinate system of the View into that of the display screen. The transformation is computed by composing the View's transformation with all transformations along its superView chain. It is sent by View|displayTransformation when the View is unlocked (see View|unlock).
	computeInsetDisplayBox Compute the View's inset display box by intersecting the superView's inset display box with the View's window transformed to display coordinates and then inseting the result by the border width. It is sent by View|insetDisplayBox if the inset display box is nil. The insetDisplayBox points are truncated to prevent sending floating point numbers to QuickDraw which will die.
	getController Answer the View's controller if one exists. nil indicates that the default controller is to be used.
	getViewport Answer the Rectangle representing the View's viewport (in the coordinate system of the superclass). If no viewport has been specified, the View's window transformed into the superView's coordinate system is saved and returned. It should be used by methods of View and subclasses (instead of directly referring to the viewport) unless it is known that a viewport actually exists. It should not be used outside of View or subclasses because the viewport is not sharable.
	getWindow Answer the Rectangle that represents the window of this View. If no window has been specified, a default window (see View|defaultWindow) is created, saved, and returned. Should be used by methods of View and subclasses to access the View window instead of directly accessing the field unless it is known that a window actually exists. It is not to be used outside of View (or subclasses) because the window is not sharable. View|window should be used for outside access to the window.
	isCyclic: Answer true if aView is the same as this View or its superView, false otherwise.
	setTransformation: Set the View's local transformation to aTransformation, unlock the View (see View|unlock), and set the viewport to undefined (this forces it to be recomputed when needed). Should be used instead of setting the transformation directly.
	setWindow: Set the View's window to aWindow and unlock the View (see View|unlock). View|setWindow should be used by methods of View and subclasses to set the View window (rather than directly setting the instance variable) to insure that the View is unlocked.
	superView: Set the View's superView to aView and unlock the View (see View|unlock). It is sent by View|addSubView: in order to properly set all the links.

	scrolling	top
	scrollBy: The x component of aPoint specifies the amount of scrolling in the x direction; the y component specifies the amount of scrolling in the y direction. The amounts are specified in the receiver's local coordinate system. Scroll the receiver up or down, left or right. The window of the receiver is kept stationary and the subViews and other objects in the receiver are translated relative to it. Scrolling doesn't change the insetDisplayBox or the viewport since the change in the transformation is canceled by the change in the window. In other words, all display objects in the view, except the window, are translated by the scrolling operation. Note: subclasses may override to return false if no scrolling takes place.

	subView access	top
	firstSubView Answer the first subView in the receiver's list of subViews if it is not empty, else nil.
	lastSubView Answer the last subView in the receiver's list of subViews if it is not empty, else nil.
	resetSubViews Set the list of subviews to an empty collection.
	subViewContaining: Answer the first subView that contains aPoint within its window and answer nil, otherwise. It is typically sent from a Controller in order to determine where to pass control (usually to the Controller of the View returned by View|subViewContaining:).
	subViewSatisfying: Return the first subview that satisfies aBlock, or nil if none does. 1/31/96 sw
	subViews Answer the receiver's collection of subViews.
	textEditorView Return the first view in the receiver whose controller is a ParagraphEdior, or nil if none. 1/31/96 sw

	subView inserting	top
	addSubView: Remove aView from the tree of Views it is in (if any) and adds it to the rear of the list of subViews of the receiver. Set the superView of aView to be the receiver. It is typically used to build up a hierarchy of Views (a structured picture). An error notification is generated if aView is the same as the receiver or its superView, and so on.
	addSubView:above: Adds aView (see View|addSubView:) so that it lies above topView.
	addSubView:align:with: Add aView to the receiver's list of subViews (see View|addSubView:) and translate aView so that aPoint1 coincides with aPoint2. It is typically used to build up a hierarchy of Views (a structured picture). Normally, aPoint1 is a point on aView's viewport (e.g. aView viewport topLeft), and aPoint2 is either an arbitrary point in the receiver's coordinate system or a point on the receiver's window (e.g., self window topRight).
	addSubView:below: Add the argument, aSubView, (see View|addSubView:) so that it lies below the view, topView.
	addSubView:ifCyclic: Remove aView from the tree of Views it is in (if any) and add it to the rear of the list of subViews of the receiver. Set the superView of aView to be the receiver. It is typically used to build up a hierarchy of Views (a structured picture). An error notification is generated if aView is the same as the receiver or its superView, and so on.
	addSubView:toLeftOf: Adds aView (see addSubView:) so that it lies to the right of rightView.
	addSubView:toRightOf: Add the argument, aSubView, (see View|addSubView:) so that it lies to the right of the view, leftView.
	addSubView:viewport: Add aView to the receiver's list of subViews (see View|addSubView:) and applies to aView a scale and translation computed from its window and aViewport (such that its window fills aViewport).
	addSubView:window:viewport: Add aView to the receiver's list of subViews (see View|addSubView:) and applies to aView a scale and translation computed from aWindow and aViewport (such that aWindow fills aViewport).

	subView removing	top
	releaseSubView: Delete aView from the receiver's list of subViews and send it the message 'release' (so that it can break up cycles with subViews, etc.).
	releaseSubViews Release (see View|releaseSubView:) all subViews in the receiver's list of subViews.
	removeFromSuperView Delete the receiver from its superView's collection of subViews.
	removeSubView: Delete aView from the receiver's list of subViews. If the list of subViews does not contain aView, create an error notification.
	removeSubViews Delete all the receiver's subViews.

	superView access	top
	isTopView Answer whether the receiver is a top view, that is, if it has no superView.
	superView Answer the superView of the receiver.
	topView Answer the root of the tree of Views in which the receiver is a node. The root of the tree is found by going up the superView path until reaching a View whose superView is nil.

	testing	top
	canDiscardEdits Return true if this pane is not dirty.
	containsPoint: Answer whether aPoint is within the receiver's display box. It is sent to a View's subViews by View|subViewAt: in order to determine which subView contains the cursor point (so that, for example, control can be pass down to that subView's controller).
	hasUnacceptedEdits Return true if this view has unaccepted edits.
	isObscured

	transforming	top
	align:with: Add a translation of (aPoint2 - aPoint1) to the receiver's local transformation. The point in the receiver's coordinate system that previously was transformed to aPoint1 in the superView's coordinate system will now be transformed to aPoint2 in the superView's coordinate system. Other points will be translated by the same amount. It is normally used when adding subViews to their superView in order to line up the Viewport of one subView with that of another subView (see View|addSubView:align:with:). aPoint1 and aPoint2 are usually points on the viewports that are to be aligned. For example, 'subView2 align: subView2 viewport topLeft with: subView1 viewport topRight' would be used to place the viewport of subView2 next to the viewport of subView1 with the topLeft and topRight corners, respectively, coinciding. It is also possible to align the viewport of a subView with the window of the superView, e.g., 'subView align: subView viewport center with: superView window center'. View|align:with: assumes that the view has been properly scaled, if necessary, to match its superView (see View|scaleBy:). Typically, the coordinate systems of the receiver and its superView will differ only by a translation offset so that no scaling is necessary.
	scale:translation: The x component of aScale (a Point) specifies the scale (translation) in the x direction; the y component specifies the scale (translation) in the y direction. aScale can optionally be an instance of Integer or Float in order to specify uniform scaling in both directions. Create a new local transformation for the receiver with a scale factor of aScale and a translation offset of aTranslation. When the transformation is applied (see View|transform:), the scale is applied first, followed by the translation. It is typically used when building a superView from its subViews in order to line up the viewports of the subViews in the desired way. If no scaling is required between subView and superView, then View|align:with: is often more convenient to use.
	scaleBy: The x component of aScale (a Point) specifies the scale in the x direction; the y component specifies the scale in the y direction. aScale can, optionally, be an instance of Integer or Float in order to specify uniform scaling in both directions. Scales the View by aScale. The scale is concatenated with the current transformation of the receiver and is applied when View|transform is sent. This happens automatically in the process of displaying the receiver, for example.
	transform: Apply the local transformation of the receiver to anObject and answer the resulting transformation. It is used to get the superView coordinates of an object. For example, the viewport is equal to the window transformed.
	transformation Answer a copy of the receiver's local transformation.
	transformation: Set the receiver's local transformation to a copy of aTransformation, unlock the receiver (see View|unlock) and set the viewport to undefined (this forces it to be recomputed when needed).
	translateBy: Translate the receiver by aPoint. The translation is concatenated with the current transformation of the receiver and is applied when View|transform is sent. This happens automatically in the process of displaying the receiver.
	window:viewport: Set the receiver's window to aWindow, set its viewport to aViewport, and create a new local transformation for the receiver based on aWindow and aViewport. The receiver is scaled and translated so that aWindow, when transformed, coincides with aViewport. It is used to position a subView's window within some specific region of its superView's area. For example, 'subView window: aRectangle1 viewport: aRectangle2' sets subView's window to aRectangle1, its viewport to aRectangle2, and its local transformation to one that transforms aRectangle1 to aRectange2.

	updating	top
	update Normally sent by the receiver's model in order to notify the receiver of a change in the model's state. Subclasses implement this message to do particular update actions. A typical action that might be required is to redisplay the receiver.
	update: Normally sent by the receiver's model in order to notify the receiver of a change in the model's state. Subclasses implement this message to do particular update actions. A typical action that might be required is to redisplay the receiver.

	viewport access	top
	viewport Answer a copy of the receiver's viewport.

	window access	top
	defaultWindow Build the minimum Rectangle that encloses all the windows of the receiver's subViews. The answer is a Rectangle obtained by expanding this minimal Rectangle by the borderWidth of the receiver. If the receiver has no subViews, then a Rectangle enclosing the entire display screen is answered. It is used internally by View methods if no window has been specified for the View. Specialized subclasses of View should redefine View|defaultWindow to handle the default case for instances that have no subViews.
	insetWindow Answer a Rectangle that is obtained by insetting the receiver's window rectangle by the border width.
	window Answer a copy of the receiver's window.
	window: Set the receiver's window to a copy of aWindow.

	instance creation	top
	new Answer an initialized instance of me. The transformation is an identity transformation, the borderWidth is 0, the borderColor is black, and the insideColor is transparent.