components/NavigationDrawer/src/MDCBottomDrawerPresentationController.h - external/github.com/material-components/material-components-ios.git - Git at Google

 // Copyright 2018-present the Material Components for iOS authors. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 // http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.

 #import <UIKit/UIKit.h>

 // TODO(b/151929968): Delete import of delegate headers when client code has been migrated to no
 // longer import delegates as transitive dependencies.
 #import "MDCBottomDrawerPresentationControllerDelegate.h"
 #import "MDCBottomDrawerState.h"
 #import "MaterialShadowElevations.h"

 @class MDCBottomDrawerPresentationController;
 @protocol MDCBottomDrawerPresentationControllerDelegate;

 /**
  The presentation controller to use for presenting an MDC bottom drawer.
  */
 @interface MDCBottomDrawerPresentationController : UIPresentationController

 /**
  Setting the tracking scroll view allows the drawer scroll the content seamlessly as part of
  the drawer movement. This allows the provided scroll view to load the visible
  content as the drawer moves, and therefore not load all the content at once
  and allow to reuse the cells when using a UICollectionView or UITableView.
  */
 @property(nonatomic, weak, nullable) UIScrollView *trackingScrollView;

 /**
  The color applied to the background scrim.
  */
 @property(nonatomic, strong, nullable) UIColor *scrimColor;

 /**
  Delegate to tell the presenter when the drawer will change state.
  */
 @property(nonatomic, weak, nullable) id<MDCBottomDrawerPresentationControllerDelegate> delegate;

 /**
  A Boolean value that determines whether the top handle of the drawer is hidden.
  Default is YES.
  */
 @property(nonatomic, assign, getter=isTopHandleHidden) BOOL topHandleHidden;

 /**
  The color applied to the top handle.
  Note: Make sure that topHandleHidden is set to NO to have the top handle be visible.
  Default is set to 0xE0E0E0.
  */
 @property(nonatomic, strong, nullable) UIColor *topHandleColor;

 /**
  The absolute height in points to which the drawer may expand initially.

  Defaults to 0, indicating no value has been set and it should use the default behavior of 50%
  of the screen's height.

  If the value is larger than the container's height, this will result the drawer being presented
  at fullscreen.

  Note: When TraitCollection is UIUserInterfaceSizeClassCompact or when using
  VoiceOver or SwitchControl, the drawer will always present at full screen.
  */
 @property(nonatomic, assign) CGFloat maximumInitialDrawerHeight;

 /**
  The absolute height in points to which the drawer may expand when a user scrolls.

  Defaults to 0, indicating no value has been set and it should use the default behavior of 100% of
  the screen's height.

  If the value is larger than the container's height, this will allow the drawer to be scrolled to
  the full height of the container.
  */
 @property(nonatomic, assign) CGFloat maximumDrawerHeight;

 /**
  A flag allowing clients to opt-out of the drawer closing when the user taps outside the content.

  @default YES The drawer should dismiss on tap.
  */
 @property(nonatomic, assign) BOOL dismissOnBackgroundTap;

 /**
  A flag allowing clients to opt-in to handling background touch events.

  @default NO The drawer will not forward touch events.

  @discussion If set to YES and the delegate is an instance of @UIResponder, then the touch events
  that are not handled by the drawer content (aka touches on the background view) will be forwarded
  along to the delegate.

  Note: @dismissOnBackgroundTap should also be set to NO so that the events will propagate properly
  from the background tap through to the delegate. Setting @shouldForwardBackgroundTouchEvents to YES
  will also set @dismissOnBackgroundTap to NO.
  */
 @property(nonatomic, assign) BOOL shouldForwardBackgroundTouchEvents;

 /**
  A flag allowing clients to opt-in to the drawer adding additional height to the content to include
  the bottom safe area inset. This will remove the need for clients to calculate their content size
  with the bottom safe area when setting the preferredContentSize of the contentViewController.
  Defaults to NO.
  */
 @property(nonatomic, assign) BOOL shouldIncludeSafeAreaInContentHeight;

 /**
  A flag allowing clients to opt-in to adding additional height to the initial presentation of the
  drawer to include the bottom safe area inset. This will remove the need for clients to calculate
  their desired maximum height with the bottom safe area when setting the maximumInitialDrawerHeight.
  Defaults to NO.
  */
 @property(nonatomic, assign) BOOL shouldIncludeSafeAreaInInitialDrawerHeight;

 /**
  This flag allows clients to have the drawer content scroll below the status bar when no header is
  provided.

  Note: This flag is only applicable when @c headerViewController is nil. If @c headerViewController
  is non-nil, setting this flag to YES will have no effect.

  Defaults to NO.
 */
 @property(nonatomic, assign) BOOL shouldUseStickyStatusBar;

 /**
  Determines the behavior of the drawer when the content size changes.
  If enabled, the drawer will automatically adjust the visible height as needed, otherwise the
  visible height will not be changed to reflect the updated content height.
  Defaults to NO.
  */
 @property(nonatomic, assign) BOOL shouldAdjustOnContentSizeChange;

 /**
  A boolean value that indicates whether the drawer is currently the full height of the window.
  */
 @property(nonatomic, readonly) BOOL contentReachesFullscreen;

 /**
  The drawer's top shadow color. Defaults to black with 20% opacity.
  */
 @property(nonatomic, strong, nonnull) UIColor *drawerShadowColor;

 /**
  The drawer's elevation. Defaults to MDCShadowElevationNavDrawer.
  */
 @property(nonatomic, assign) MDCShadowElevation elevation;

 /**
  Determines if the header should always expand as it approaches the top of the screen.
  If the content height is smaller than the screen height then the header will not expand unless this
  flag is enabled.
  Defaults to NO.
  */
 @property(nonatomic, assign) BOOL shouldAlwaysExpandHeader;

 /**
  Whether layout adjustments should be made to support iPad Slide Over.

  Defaults to NO to maintain the same behavior that existed before this property
  was added and to allow apps to migrate on their own schedule.
  */
 @property(nonatomic) BOOL adjustLayoutForIPadSlideOver;

 /**
  Whether to display mobile landscape view as fullscreen.

  When enabled, the drawer will fill the screen in landscape on mobile devices.

  Defaults to YES.
 */
 @property(nonatomic) BOOL shouldDisplayMobileLandscapeFullscreen;

 /** Whether the drawer allows the user to drag it or not. */
 @property(nonatomic) BOOL userDraggingEnabled;

 /**
  Sets the content offset Y of the drawer's content. If contentOffsetY is set to 0, the
  drawer will scroll to the start of its content.

  @param contentOffsetY the content offset Y of the scroll view.
  @param animated a bool if to animate the scrolling.
  */
 - (void)setContentOffsetY:(CGFloat)contentOffsetY animated:(BOOL)animated;

 /**
  Expands the drawer to fullscreen with animation.

  note: If the drawer has less content than the full screen,
  this method will still expand the drawer to fullscreen.

  @param duration The total duration of the animations, measured in seconds. If you specify a
  negative value or 0, the changes are made without animating them.

  @param completion A block object to be executed when the animation sequence ends. This block has
  no return value and takes a single Boolean argument that indicates whether or not the animations
  actually finished before the completion handler was called. If the duration of the animation is 0,
  this block is performed at the beginning of the next run loop cycle. This parameter may be NULL.
  */
 - (void)expandToFullscreenWithDuration:(CGFloat)duration
                             completion:(void (^__nullable)(BOOL finished))completion;

 /**
  A block that is invoked when the @c MDCBottomDrawerPresentationController  receives a call to @c
  traitCollectionDidChange:. The block is called after the call to the superclass.
  */
 @property(nonatomic, copy, nullable) void (^traitCollectionDidChangeBlock)
     (MDCBottomDrawerPresentationController *_Nullable presentationController,
      UITraitCollection *_Nullable previousTraitCollection);
 @end
	// Copyright 2018-present the Material Components for iOS authors. All Rights Reserved.
	//
	// Licensed under the Apache License, Version 2.0 (the "License");
	// you may not use this file except in compliance with the License.
	// You may obtain a copy of the License at
	//
	// http://www.apache.org/licenses/LICENSE-2.0
	//
	// Unless required by applicable law or agreed to in writing, software
	// distributed under the License is distributed on an "AS IS" BASIS,
	// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	// See the License for the specific language governing permissions and
	// limitations under the License.

	#import <UIKit/UIKit.h>

	// TODO(b/151929968): Delete import of delegate headers when client code has been migrated to no
	// longer import delegates as transitive dependencies.
	#import "MDCBottomDrawerPresentationControllerDelegate.h"
	#import "MDCBottomDrawerState.h"
	#import "MaterialShadowElevations.h"

	@class MDCBottomDrawerPresentationController;
	@protocol MDCBottomDrawerPresentationControllerDelegate;

	/**
	The presentation controller to use for presenting an MDC bottom drawer.
	*/
	@interface MDCBottomDrawerPresentationController : UIPresentationController

	/**
	Setting the tracking scroll view allows the drawer scroll the content seamlessly as part of
	the drawer movement. This allows the provided scroll view to load the visible
	content as the drawer moves, and therefore not load all the content at once
	and allow to reuse the cells when using a UICollectionView or UITableView.
	*/
	@property(nonatomic, weak, nullable) UIScrollView *trackingScrollView;

	/**
	The color applied to the background scrim.
	*/
	@property(nonatomic, strong, nullable) UIColor *scrimColor;

	/**
	Delegate to tell the presenter when the drawer will change state.
	*/
	@property(nonatomic, weak, nullable) id<MDCBottomDrawerPresentationControllerDelegate> delegate;

	/**
	A Boolean value that determines whether the top handle of the drawer is hidden.
	Default is YES.
	*/
	@property(nonatomic, assign, getter=isTopHandleHidden) BOOL topHandleHidden;

	/**
	The color applied to the top handle.
	Note: Make sure that topHandleHidden is set to NO to have the top handle be visible.
	Default is set to 0xE0E0E0.
	*/
	@property(nonatomic, strong, nullable) UIColor *topHandleColor;

	/**
	The absolute height in points to which the drawer may expand initially.

	Defaults to 0, indicating no value has been set and it should use the default behavior of 50%
	of the screen's height.

	If the value is larger than the container's height, this will result the drawer being presented
	at fullscreen.

	Note: When TraitCollection is UIUserInterfaceSizeClassCompact or when using
	VoiceOver or SwitchControl, the drawer will always present at full screen.
	*/
	@property(nonatomic, assign) CGFloat maximumInitialDrawerHeight;

	/**
	The absolute height in points to which the drawer may expand when a user scrolls.

	Defaults to 0, indicating no value has been set and it should use the default behavior of 100% of
	the screen's height.

	If the value is larger than the container's height, this will allow the drawer to be scrolled to
	the full height of the container.
	*/
	@property(nonatomic, assign) CGFloat maximumDrawerHeight;

	/**
	A flag allowing clients to opt-out of the drawer closing when the user taps outside the content.

	@default YES The drawer should dismiss on tap.
	*/
	@property(nonatomic, assign) BOOL dismissOnBackgroundTap;

	/**
	A flag allowing clients to opt-in to handling background touch events.

	@default NO The drawer will not forward touch events.

	@discussion If set to YES and the delegate is an instance of @UIResponder, then the touch events
	that are not handled by the drawer content (aka touches on the background view) will be forwarded
	along to the delegate.

	Note: @dismissOnBackgroundTap should also be set to NO so that the events will propagate properly
	from the background tap through to the delegate. Setting @shouldForwardBackgroundTouchEvents to YES
	will also set @dismissOnBackgroundTap to NO.
	*/
	@property(nonatomic, assign) BOOL shouldForwardBackgroundTouchEvents;

	/**
	A flag allowing clients to opt-in to the drawer adding additional height to the content to include
	the bottom safe area inset. This will remove the need for clients to calculate their content size
	with the bottom safe area when setting the preferredContentSize of the contentViewController.
	Defaults to NO.
	*/
	@property(nonatomic, assign) BOOL shouldIncludeSafeAreaInContentHeight;

	/**
	A flag allowing clients to opt-in to adding additional height to the initial presentation of the
	drawer to include the bottom safe area inset. This will remove the need for clients to calculate
	their desired maximum height with the bottom safe area when setting the maximumInitialDrawerHeight.
	Defaults to NO.
	*/
	@property(nonatomic, assign) BOOL shouldIncludeSafeAreaInInitialDrawerHeight;

	/**
	This flag allows clients to have the drawer content scroll below the status bar when no header is
	provided.

	Note: This flag is only applicable when @c headerViewController is nil. If @c headerViewController
	is non-nil, setting this flag to YES will have no effect.

	Defaults to NO.
	*/
	@property(nonatomic, assign) BOOL shouldUseStickyStatusBar;

	/**
	Determines the behavior of the drawer when the content size changes.
	If enabled, the drawer will automatically adjust the visible height as needed, otherwise the
	visible height will not be changed to reflect the updated content height.
	Defaults to NO.
	*/
	@property(nonatomic, assign) BOOL shouldAdjustOnContentSizeChange;

	/**
	A boolean value that indicates whether the drawer is currently the full height of the window.
	*/
	@property(nonatomic, readonly) BOOL contentReachesFullscreen;

	/**
	The drawer's top shadow color. Defaults to black with 20% opacity.
	*/
	@property(nonatomic, strong, nonnull) UIColor *drawerShadowColor;

	/**
	The drawer's elevation. Defaults to MDCShadowElevationNavDrawer.
	*/
	@property(nonatomic, assign) MDCShadowElevation elevation;

	/**
	Determines if the header should always expand as it approaches the top of the screen.
	If the content height is smaller than the screen height then the header will not expand unless this
	flag is enabled.
	Defaults to NO.
	*/
	@property(nonatomic, assign) BOOL shouldAlwaysExpandHeader;

	/**
	Whether layout adjustments should be made to support iPad Slide Over.

	Defaults to NO to maintain the same behavior that existed before this property
	was added and to allow apps to migrate on their own schedule.
	*/
	@property(nonatomic) BOOL adjustLayoutForIPadSlideOver;

	/**
	Whether to display mobile landscape view as fullscreen.

	When enabled, the drawer will fill the screen in landscape on mobile devices.

	Defaults to YES.
	*/
	@property(nonatomic) BOOL shouldDisplayMobileLandscapeFullscreen;

	/** Whether the drawer allows the user to drag it or not. */
	@property(nonatomic) BOOL userDraggingEnabled;

	/**
	Sets the content offset Y of the drawer's content. If contentOffsetY is set to 0, the
	drawer will scroll to the start of its content.

	@param contentOffsetY the content offset Y of the scroll view.
	@param animated a bool if to animate the scrolling.
	*/
	- (void)setContentOffsetY:(CGFloat)contentOffsetY animated:(BOOL)animated;

	/**
	Expands the drawer to fullscreen with animation.

	note: If the drawer has less content than the full screen,
	this method will still expand the drawer to fullscreen.

	@param duration The total duration of the animations, measured in seconds. If you specify a
	negative value or 0, the changes are made without animating them.

	@param completion A block object to be executed when the animation sequence ends. This block has
	no return value and takes a single Boolean argument that indicates whether or not the animations
	actually finished before the completion handler was called. If the duration of the animation is 0,
	this block is performed at the beginning of the next run loop cycle. This parameter may be NULL.
	*/
	- (void)expandToFullscreenWithDuration:(CGFloat)duration
	completion:(void (^__nullable)(BOOL finished))completion;

	/**
	A block that is invoked when the @c MDCBottomDrawerPresentationController receives a call to @c
	traitCollectionDidChange:. The block is called after the call to the superclass.
	*/
	@property(nonatomic, copy, nullable) void (^traitCollectionDidChangeBlock)
	(MDCBottomDrawerPresentationController *_Nullable presentationController,
	UITraitCollection *_Nullable previousTraitCollection);
	@end