File indexing completed on 2024-04-28 04:20:14
0001 0002 /* 0003 Copyright (c) 2003-2007 Clarence Dang <dang@kde.org> 0004 All rights reserved. 0005 0006 Redistribution and use in source and binary forms, with or without 0007 modification, are permitted provided that the following conditions 0008 are met: 0009 0010 1. Redistributions of source code must retain the above copyright 0011 notice, this list of conditions and the following disclaimer. 0012 2. Redistributions in binary form must reproduce the above copyright 0013 notice, this list of conditions and the following disclaimer in the 0014 documentation and/or other materials provided with the distribution. 0015 0016 THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 0017 IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 0018 OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 0019 IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 0020 INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 0021 NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 0022 DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 0023 THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 0024 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 0025 THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 0026 */ 0027 0028 0029 #ifndef kpSetOverrideCursorSaver_H 0030 #define kpSetOverrideCursorSaver_H 0031 0032 0033 class QCursor; 0034 0035 0036 // 0037 // A less error-prone way of setting the override cursor, compared to 0038 // the QApplication::{set,restore}OverrideCursor() pair. 0039 // 0040 // To use this class, allocate it on the stack with the desired cursor. 0041 // 0042 // This class sets the application's override cursor to <cursor> on 0043 // construction. It restores the cursor on destruction. 0044 // 0045 // Example Usage 1 - Cursor active during the entire method: 0046 // 0047 // void method () 0048 // { 0049 // kpSetOverrideCursorSaver cursorSaver (Qt::WaitCursor); 0050 // 0051 // <potentially time-consuming operation> 0052 // 0053 // } // Stack unwinds, calling cursorSaver's destructor, 0054 // // which restores the cursor 0055 // 0056 // Example Usage 2 - Cursor active during part of the method: 0057 // 0058 // void method () 0059 // { 0060 // <some code> 0061 // 0062 // { 0063 // kpSetOverrideCursorSaver cursorSaver (Qt::WaitCursor); 0064 // 0065 // <potentially time-consuming operation> 0066 // 0067 // } // Stack unwinds, calling cursorSaver's destructor, 0068 // // which restores the cursor 0069 // 0070 // // (cursor is restored before this code executes) 0071 // <more code> 0072 // } 0073 // 0074 // Note that the kpSetOverrideCursorSaver must be defined as a local 0075 // variable inside -- not outside --- the braces containing the code the 0076 // cursor can be active over, else the destruction and cursor restoration 0077 // might not occur at the right time. In other words, the following usage 0078 // is wrong: 0079 // 0080 // INCORRECT Example Usage 2: 0081 // 0082 // void method () 0083 // { 0084 // <some code> 0085 // 0086 // kpSetOverrideCursorSaver cursorSaver (Qt::WaitCursor); 0087 // // BUG: These braces do nothing to limit the effect of cursorSaver. 0088 // { 0089 // <potentially time-consuming operation> 0090 // } 0091 // 0092 // // BUG: cursorSaver has not yet restored the cursor before this 0093 // // code executes. 0094 // <more code> 0095 // 0096 // } // Stack unwinds, calling cursorSaver's destructor, 0097 // // which restores the cursor 0098 // 0099 class kpSetOverrideCursorSaver 0100 { 0101 public: 0102 kpSetOverrideCursorSaver (const QCursor &cursor); 0103 ~kpSetOverrideCursorSaver (); 0104 }; 0105 0106 0107 #endif // kpSetOverrideCursorSaver_H