| Inherits from | |
| Conforms to | |
| Framework | /System/Library/Frameworks/UIKit.framework |
| Availability | Available in iOS 2.0 and later. |
| Declared in | UIWindow.h |
The UIWindow class defines objects (known as windows ) that manage and coordinate the windows an application displays on the screen. The two principal functions of a window are to provide an area for displaying its views and to distribute events to the views. The window is the root view in the view hierarchy. A window belongs to a level; the windows in one level appear above another level. For example, alerts appear above normal windows. Typically, there is only one window in an iOS application.
Read Windows and Views in iOS Application Programming Guide to learn how to use this class.
windowLevel property
screen property
rootViewController property
– convertPoint:toWindow:
– convertPoint:fromWindow:
– convertRect:toWindow:
– convertRect:fromWindow:
For more about Objective-C properties, see “Properties” in The Objective-C Programming Language.
A Boolean value that indicates whether the receiver is the key window for the application. (read-only)
@property(nonatomic, readonly, getter=isKeyWindow) BOOL keyWindow
UIWindow.hThe root view controller for the window.
@property(nonatomic,retain) UIViewController *rootViewController
The root view controller provides the content view of the window. Assigning a view controller to this property (either programmatically or using Interface Builder) installs the view controller’s view as the content view of the window. If the window has an existing view hierarchy, the old views are removed before the new ones are installed.
The default value of this property is nil.
UIWindow.hThe screen on which the window is currently displayed.
@property (nonatomic,retain) UIScreen *screen
By default, all windows are created on the main screen. If additional screens are attached to the device, assigning a different screen object to this property causes the window to be displayed on the new screen.
Moving windows from screen to screen is a relatively expensive operation and should not be done in performance-sensitive code. Instead, it is recommended that you change the screen before displaying the window the first time. Changing the screen of a window that has not yet been ordered onto the screen has no significant additional cost.
UIWindow.hThe receiver’s window level.
@property(nonatomic) UIWindowLevel windowLevel
Levels are ordered so that each level groups windows within it in front of those in all preceding groups. For example, alert windows appear in front of all normal-level windows. When a window enters a new level, it’s ordered in front of all its peers in that level. See “UIWindowLevel” for a list of possible values. The default value is 0.0.
UIWindow.hInvoked automatically to inform the receiver that it has become the key window; never invoke this method directly.
- (void)becomeKeyWindow
This method reestablishes the receiver’s first responder, sends the becomeKeyWindow message to that object if it responds, and posts UIWindowDidBecomeKeyNotification to the default notification center.
UIWindow.hConverts a point from the coordinate system of a given window to that of the receiver.
- (CGPoint)convertPoint:(CGPoint)point fromWindow:(UIWindow *)window
A point specifying a location in the coordinate system of window.
The window with point in its coordinate system. If nil, this method converts the point from the logical coordinate system of the screen, which is measured in points.
The point converted to the coordinate system of the receiver.
UIWindow.hConverts a point from the receiver’s coordinate system to that of another window.
- (CGPoint)convertPoint:(CGPoint)point toWindow:(UIWindow *)window
A point specifying a location in the logical coordinate system of the receiver.
The window into whose coordinate system point is to be converted. If nil, this method converts the point to the logical coordinate system of the screen, which is measured in points.
The point converted to the coordinate system of window.
UIWindow.hConverts a rectangle from the coordinate system of another window to that of the receiver.
- (CGRect)convertRect:(CGRect)rect fromWindow:(UIWindow *)window
The rectangle in the window's coordinate system.
The window with rect in its coordinate system. If nil, this method instead converts the rectangle from the logical coordinate system of the screen, which is measured in points.
The converted rectangle.
UIWindow.hConverts a rectangle from the receiver’s coordinate system to that of another window.
- (CGRect)convertRect:(CGRect)rect toWindow:(UIWindow *)window
A rectangle in the receiver's coordinate system.
The window that is the target of the conversion operation. If nil, this method instead converts the rectangle to the logical coordinate system of the screen, which is measured in points.
The converted rectangle.
UIWindow.hMakes the receiver the key window and makes that window visible.
- (void)makeKeyAndVisible
This is a convenience method to make the receiver the main window and displays it in front of other windows. You can also hide and reveal a window using the inherited hiddenUIView property.
UIWindow.hMakes the receiver the main window.
- (void)makeKeyWindow
UIWindow.hInvoked automatically when the window resigns key window status; never invoke this method directly.
- (void)resignKeyWindow
This method sends resignKeyWindow to the receiver’s first responder and posts UIWindowDidResignKeyNotification to the default notification center.
UIWindow.hDispatches events sent to the receiver by the UIApplication object to its views.
- (void)sendEvent:(UIEvent *)event
The event to process.
UIWindow.hThe positioning of windows relative to each other.
const UIWindowLevel UIWindowLevelNormal; const UIWindowLevel UIWindowLevelAlert; const UIWindowLevel UIWindowLevelStatusBar; typedef CGFloat UIWindowLevel;
UIWindowLevelNormalThe default level.
Available in iOS 2.0 and later.
Declared in UIWindow.h.
UIWindowLevelAlertThe level for an alert view.
Available in iOS 2.0 and later.
Declared in UIWindow.h.
UIWindowLevelStatusBarThe level for a status window.
Available in iOS 2.0 and later.
Declared in UIWindow.h.
The stacking of levels takes precedence over the stacking of windows within each level. That is, even the bottom window in a level obscures the top window of the next level down. Levels are listed in order from lowest to highest.
Keys used to get values from the user information dictionary of keyboard notifications.
NSString *const UIKeyboardFrameBeginUserInfoKey; NSString *const UIKeyboardFrameEndUserInfoKey; NSString *const UIKeyboardAnimationDurationUserInfoKey; NSString *const UIKeyboardAnimationCurveUserInfoKey; // Deprecated in iOS 3.2 and later. NSString *const UIKeyboardCenterBeginUserInfoKey; NSString *const UIKeyboardCenterEndUserInfoKey; NSString *const UIKeyboardBoundsUserInfoKey;
UIKeyboardFrameBeginUserInfoKeyThe key for an NSValue object containing a CGRect that identifies the start frame of the keyboard in screen coordinates. These coordinates do not take into account any rotation factors applied to the window’s contents as a result of interface orientation changes. Thus, you may need to convert the rectangle to window coordinates (using the convertRect:fromWindow: method) or to view coordinates (using the convertRect:fromView: method) before using it.
Available in iOS 3.2 and later.
Declared in UIWindow.h.
UIKeyboardFrameEndUserInfoKeyThe key for an NSValue object containing a CGRect that identifies the end frame of the keyboard in screen coordinates. These coordinates do not take into account any rotation factors applied to the window’s contents as a result of interface orientation changes. Thus, you may need to convert the rectangle to window coordinates (using the convertRect:fromWindow: method) or to view coordinates (using the convertRect:fromView: method) before using it.
Available in iOS 3.2 and later.
Declared in UIWindow.h.
UIKeyboardAnimationCurveUserInfoKeyThe key for an NSValue object containing a UIViewAnimationCurve constant that defines how the keyboard will be animated onto or off the screen.
Available in iOS 3.0 and later.
Declared in UIWindow.h.
UIKeyboardAnimationDurationUserInfoKeyThe key for an NSValue object containing a double that identifies the duration of the animation in seconds.
Available in iOS 3.0 and later.
Declared in UIWindow.h.
UIKeyboardCenterBeginUserInfoKeyThe key for an NSValue object containing a CGPoint that is the center of the keyboard in window coordinates before animation. These coordinates actually take into account any rotation factors applied to the window’s contents as a result of interface orientation changes. Thus, the center point of the keyboard is different in portrait versus landscape orientations.
Use the UIKeyboardFrameBeginUserInfoKey key instead.
Available in iOS 2.0 and later.
Deprecated in iOS 3.2.
Declared in UIWindow.h.
UIKeyboardCenterEndUserInfoKeyThe key for an NSValue object containing a CGPoint that is the center of the keyboard in window coordinates after animation. These coordinates take into account any rotation factors applied to the window’s contents as a result of interface orientation changes. Thus, the center point of the keyboard is different in portrait versus landscape orientations.
Use the UIKeyboardFrameEndUserInfoKey key instead.
Available in iOS 2.0 and later.
Deprecated in iOS 3.2.
Declared in UIWindow.h.
UIKeyboardBoundsUserInfoKeyThe key for an NSValue object containing a CGRect that identifies the bounds rectangle of the keyboard in window coordinates. This value is sufficient for obtaining the size of the keyboard. If you want to get the origin of the keyboard on the screen (before or after animation) use the values obtained from the user info dictionary through the UIKeyboardCenterBeginUserInfoKey or UIKeyboardCenterEndUserInfoKey constants.
Use the UIKeyboardFrameBeginUserInfoKey or UIKeyboardFrameEndUserInfoKey key instead.
Available in iOS 2.0 and later.
Deprecated in iOS 3.2.
Declared in UIWindow.h.
Posted when an UIWindow object becomes visible.
The notification object is the window object that has become visible. This notification does not contain a userInfo dictionary.
UIWindow.hPosted when an UIWindow object becomes hidden.
The notification object is the window object that has become hidden. This notification does not contain a userInfo dictionary.
UIWindow.hPosted whenever a UIWindow object becomes the key window.
The notification object is the window object that has become key. This notification does not contain a userInfo dictionary.
UIWindow.hPosted whenever a UIWindow object resigns its status as main window.
The notification object is the window object that has resigned its main window status. This notification does not contain a userInfo dictionary.
UIWindow.hPosted before a UIWindow object is displayed.
The notification object is nil. The userInfo dictionary contains information about the keyboard. Use the keys described in “Keyboard Notification User Info Keys” to get the location and size of the keyboard from the userInfo dictionary.
UIWindow.hPosted after a UIWindow object is displayed.
The notification object is nil. The userInfo dictionary contains information about the keyboard. Use the keys described in “Keyboard Notification User Info Keys” to get the location and size of the keyboard from the userInfo dictionary.
UIWindow.hPosted before a UIWindow object is hidden.
The notification object is nil. The userInfo dictionary contains information about the keyboard. Use the keys described in “Keyboard Notification User Info Keys” to get the location and size of the keyboard from the userInfo dictionary.
UIWindow.hPosted after a UIWindow object is hidden.
The notification object is nil. The userInfo dictionary contains information about the keyboard. Use the keys described in “Keyboard Notification User Info Keys” to get the location and size of the keyboard from the userInfo dictionary.
UIWindow.hLast updated: 2010-05-06