WebCore/html/HTMLScriptRunner.h
changeset 0 4f2f89ce4247
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/WebCore/html/HTMLScriptRunner.h	Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,129 @@
+/*
+ * Copyright (C) 2010 Google, Inc. All Rights Reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#ifndef HTMLScriptRunner_h
+#define HTMLScriptRunner_h
+
+#include "CachedResourceClient.h"
+#include "CachedResourceHandle.h"
+#include <wtf/Noncopyable.h>
+#include <wtf/PassRefPtr.h>
+
+namespace WebCore {
+
+class CachedResourceClient;
+class CachedScript;
+class Document;
+class Element;
+class Frame;
+class HTMLScriptRunnerHost;
+class ScriptSourceCode;
+
+class HTMLScriptRunner : public Noncopyable {
+public:
+    HTMLScriptRunner(Document*, HTMLScriptRunnerHost*);
+    ~HTMLScriptRunner();
+
+    // Processes the passed in script and any pending scripts if possible.
+    bool execute(PassRefPtr<Element> scriptToProcess, int scriptStartLine);
+
+    bool executeScriptsWaitingForLoad(CachedResource*);
+    bool hasScriptsWaitingForStylesheets() const { return m_hasScriptsWaitingForStylesheets; }
+    bool executeScriptsWaitingForStylesheets();
+
+    bool inScriptExecution() { return !!m_scriptNestingLevel; }
+
+private:
+    // A container for an external script which may be loaded and executed.
+    //
+    // A CachedResourceHandle alone does not prevent the underlying CachedResource
+    // from purging its data buffer. This class holds a dummy client open for its
+    // lifetime in order to guarantee that the data buffer will not be purged.
+    //
+    // FIXME: Finish turning this into a proper class.
+    class PendingScript : public CachedResourceClient, Noncopyable {
+    public:
+        PendingScript()
+            : startingLineNumber(0)
+            , m_watchingForLoad(false)
+        {
+        }
+
+        ~PendingScript();
+
+        PassRefPtr<Element> releaseElementAndClear();
+
+        bool watchingForLoad() const { return m_watchingForLoad; }
+        void setWatchingForLoad(bool b) { m_watchingForLoad = b; }
+
+        CachedScript* cachedScript() const;
+        void setCachedScript(CachedScript*);
+
+        virtual void notifyFinished(CachedResource*)
+        {
+        }
+
+        RefPtr<Element> element;
+        int startingLineNumber; // Only used for inline script tags.
+        // HTML5 has an isReady parameter, however isReady ends up equivalent to
+        // m_document->haveStylesheetsLoaded() && cachedScript->isLoaded()
+
+    private:
+        bool m_watchingForLoad;
+        CachedResourceHandle<CachedScript> m_cachedScript;
+    };
+
+    Frame* frame() const;
+
+    bool haveParsingBlockingScript() const;
+    bool executeParsingBlockingScripts();
+    void executePendingScript();
+
+    void requestScript(Element*);
+    void runScript(Element*, int startingLineNumber);
+
+    // Helpers for dealing with HTMLScriptRunnerHost
+    void watchForLoad(PendingScript&);
+    void stopWatchingForLoad(PendingScript&);
+    void executeScript(Element*, const ScriptSourceCode&);
+
+    bool isPendingScriptReady(const PendingScript&);
+    ScriptSourceCode sourceFromPendingScript(const PendingScript&, bool& errorOccurred);
+
+    Document* m_document;
+    HTMLScriptRunnerHost* m_host;
+    PendingScript m_parsingBlockingScript;
+    unsigned m_scriptNestingLevel;
+
+    // We only want stylesheet loads to trigger script execution if script
+    // execution is currently stopped due to stylesheet loads, otherwise we'd
+    // cause nested script execution when parsing <style> tags since </style>
+    // tags can cause Document to call executeScriptsWaitingForStylesheets.
+    bool m_hasScriptsWaitingForStylesheets;
+};
+
+}
+
+#endif