1/*
2 * Copyright (c) 1999-2000, Eric Moon.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions, and the following disclaimer.
11 *
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions, and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * 3. The name of the author may not be used to endorse or promote products
17 *    derived from this software without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR "AS IS" AND ANY EXPRESS OR
20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21 * OF TITLE, NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
23 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
24 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
25 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
26 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
27 * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31
32// MouseTrackingHelpers.h
33// e.moon 8mar99
34//
35// Some helper classes for mouse tracking, designed to make
36// it easier to delegate drag operations to a parent class
37// (especially useful for pane-separator bars & other operations
38//  in which a view is moved or resized as the user drags
39//  within it.)
40//
41// HISTORY
42//   e.moon 11may99: fixed m_bTracking bug (not init'd in ctor)
43//                   fixed mouseTrackingBegin() documentation
44//                   (point is in view, not screen, coords)
45
46#ifndef __MouseTrackingHelpers_H__
47#define __MouseTrackingHelpers_H__
48
49#include <View.h>
50
51#include "cortex_defs.h"
52__BEGIN_CORTEX_NAMESPACE
53
54class MouseTrackingSourceView;
55
56// interface for a mouse-tracking destination
57class IMouseTrackingDestination {
58public:							// operations
59	IMouseTrackingDestination() { }
60	virtual ~IMouseTrackingDestination() { }
61	// a MouseTrackingSourceView has started tracking the mouse
62	// (point is in pSource view coordinates)
63	virtual void mouseTrackingBegin(
64		MouseTrackingSourceView* pSource,
65		uint32 buttons,
66		BPoint point)=0;
67
68	// mouse-tracking update from child view
69	// (point is in screen coordinates)
70	virtual void mouseTrackingUpdate(
71		uint32 buttons,
72		float xDelta,
73		float yDelta,
74		BPoint point)=0;
75
76	// mouse-tracking done
77	virtual void mouseTrackingEnd()=0;
78};
79
80// mouse-tracking 'source' view
81// hands off to a destination view (by default its immediate
82// parent)
83
84class MouseTrackingSourceView : public BView {
85	typedef BView _inherited;
86
87public:							// types & constants
88	// these bits determine which mouse axes will be tracked
89	// (ie. if TRACK_HORIZONTAL isn't set, mouseTrackUpdate()
90	//  will always be called with xDelta == 0.0)
91	enum mouse_tracking_flag_t {
92		TRACK_HORIZONTAL = 1,
93		TRACK_VERTICAL = 2
94	};
95
96public:								// ctor/dtor
97	MouseTrackingSourceView(
98		BRect frame,
99		const char* pName,
100		uint32 resizeMode=B_FOLLOW_LEFT|B_FOLLOW_TOP,
101		uint32 flags=B_WILL_DRAW|B_FRAME_EVENTS,
102		uint32 trackingFlags=TRACK_HORIZONTAL|TRACK_VERTICAL);
103
104	~MouseTrackingSourceView();
105
106	bool isTracking() const { return m_bTracking; }
107
108	// get mouse-down point in screen coordinates; returns
109	// B_OK on success, or B_ERROR if no longer tracking
110	// the mouse.
111	status_t getTrackingOrigin(BPoint* poPoint) const;
112
113	// fetch/set the destination handler
114	// (if not yet attached to a window, or if no parent
115	// implements IMouseTrackDestination, trackingDestination()
116	// returns 0)
117	//
118	// setting the destination handler isn't allowed if a tracking
119	// operation is currently in progress
120
121	IMouseTrackingDestination* trackingDestination() const {
122		return m_pDest;
123	}
124	status_t setTrackingDestination(IMouseTrackingDestination* pDest);
125
126public:								// BView impl.
127
128	// handle mouse events
129	virtual void MouseDown(BPoint point);
130	virtual void MouseMoved(BPoint point, uint32 transit,
131		const BMessage* pMsg);
132	virtual void MouseUp(BPoint point);
133
134	// look for a default destination
135	virtual void AttachedToWindow();
136
137/*
138	// track current frame rectangle
139	virtual void FrameResized(float width, float height);
140*/
141protected:							// members
142
143	IMouseTrackingDestination*		m_pDest;
144	uint32				m_trackingFlags;
145
146	// mouse-tracking state
147	bool						m_bTracking;
148	BPoint				m_prevPoint; // in screen coords
149	BPoint				m_initPoint; // in screen coords
150
151//	BRect					m_prevFrame;
152};
153
154__END_CORTEX_NAMESPACE
155#endif /* __MouseTrackingHelpers_H__ */
156