New class: TemporaryFile, which manages a temporary file, deleting it when it goes out of scope. Also fixes for compile problems in VC7.

src/io/files/juce_TemporaryFile.cpp

@@ -0,0 +1,115 @@
+/*
+  ==============================================================================
+
+   This file is part of the JUCE library - "Jules' Utility Class Extensions"
+   Copyright 2004-9 by Raw Material Software Ltd.
+
+  ------------------------------------------------------------------------------
+
+   JUCE can be redistributed and/or modified under the terms of the GNU General
+   Public License (Version 2), as published by the Free Software Foundation.
+   A copy of the license is included in the JUCE distribution, or can be found
+   online at www.gnu.org/licenses.
+
+   JUCE is distributed in the hope that it will be useful, but WITHOUT ANY
+   WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+   A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
+
+  ------------------------------------------------------------------------------
+
+   To release a closed-source product which uses JUCE, commercial licenses are
+   available: visit www.rawmaterialsoftware.com/juce for more information.
+
+  ==============================================================================
+*/
+
+#include "../../core/juce_StandardHeader.h"
+
+BEGIN_JUCE_NAMESPACE
+
+#include "juce_TemporaryFile.h"
+#include "../../core/juce_Random.h"
+#include "../../threads/juce_Thread.h"
+
+
+//==============================================================================
+TemporaryFile::TemporaryFile (const String& suffix, const int optionFlags)
+{
+    createTempFile (File::getSpecialLocation (File::tempDirectory),
+                    T("temp_") + String (Random::getSystemRandom().nextInt()),
+                    suffix,
+                    optionFlags);
+}
+
+TemporaryFile::TemporaryFile (const File& targetFile_, const int optionFlags)
+    : targetFile (targetFile_)
+{
+    // If you use this constructor, you need to give it a valid target file!
+    jassert (targetFile != File::nonexistent);
+
+    createTempFile (targetFile.getParentDirectory(),
+                    targetFile.getFileNameWithoutExtension() + T("_temp") + String (Random::getSystemRandom().nextInt()),
+                    targetFile.getFileExtension(),
+                    optionFlags);
+}
+
+void TemporaryFile::createTempFile (const File& parentDirectory, String name,
+                                    const String& suffix, const int optionFlags)
+{
+    if ((optionFlags & useHiddenFile) != 0)
+        name = T(".") + name;
+
+    temporaryFile = parentDirectory.getNonexistentChildFile (name, targetFile.getFileExtension(),
+                                                             (optionFlags & putNumbersInBrackets) != 0);
+}
+
+TemporaryFile::~TemporaryFile()
+{
+    // Have a few attempts at deleting the file before giving up..
+    for (int i = 5; --i >= 0;)
+    {
+        if (temporaryFile.deleteFile())
+            return;
+
+        Thread::sleep (50);
+    }
+
+    // Failed to delete our temporary file! Check that you've deleted all the
+    // file output streams that were using it!
+    jassertfalse;
+}
+
+//==============================================================================
+bool TemporaryFile::overwriteTargetFileWithTemporary() const
+{
+    // This method only works if you created this object with the constructor
+    // that takes a target file!
+    jassert (targetFile != File::nonexistent);
+
+    if (temporaryFile.exists())
+    {
+        // Have a few attempts at overwriting the file before giving up..
+        for (int i = 5; --i >= 0;)
+        {
+            if (temporaryFile.moveFileTo (targetFile))
+                return true;
+
+            Thread::sleep (100);
+        }
+
+        // Failed to overwrite the new file! Make sure you've not left any
+        // file streams hanging around when you call this method!
+        jassertfalse
+    }
+    else
+    {
+        // There's no temporary file to use. If your write failed, you should
+        // probably check, and not bother calling this method.
+        jassertfalse
+    }
+
+    return false;
+}
+
+
+END_JUCE_NAMESPACE