tdf#75637: Resolve help images via a vnd.libreoffice.image UCP

...which uses the logic already available in VCL's ImplImageTree to locate the
image zip files and find fallbacks for incomplete themes and for localized
images.

Change-Id: Ic1c15fcacb6596a27a2b051093232902202bf472

1 files changed, 121 insertions, 0 deletions

diff --git a/include/vcl/implimagetree.hxx b/include/vcl/implimagetree.hxx
new file mode 100644
index 000000000000..ffab4a827f7d
--- /dev/null
+++ b/include/vcl/implimagetree.hxx
@@ -0,0 +1,121 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * This file incorporates work covered by the following license notice:
+ *
+ *   Licensed to the Apache Software Foundation (ASF) under one or more
+ *   contributor license agreements. See the NOTICE file distributed
+ *   with this work for additional information regarding copyright
+ *   ownership. The ASF licenses this file to you 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 .
+ */
+
+#ifndef INCLUDED_INCLUDE_VCL_IMPLIMAGETREE_HXX
+#define INCLUDED_INCLUDE_VCL_IMPLIMAGETREE_HXX
+
+#include <sal/config.h>
+
+#include <memory>
+#include <unordered_map>
+#include <utility>
+#include <vector>
+
+#include <com/sun/star/uno/Reference.hxx>
+#include <rtl/ustring.hxx>
+#include <vcl/bitmapex.hxx>
+#include <vcl/dllapi.h>
+
+namespace com { namespace sun { namespace star { namespace container {
+    class XNameAccess;
+} } } }
+
+class ImplImageTree {
+public:
+    VCL_DLLPUBLIC static ImplImageTree & get();
+
+    ImplImageTree();
+
+    ~ImplImageTree();
+
+    VCL_DLLPUBLIC OUString getImageUrl(
+        OUString const & name, OUString const & style, OUString const & lang);
+
+    bool loadImage(
+        OUString const & name, OUString const & style,
+        BitmapEx & bitmap, bool localized = false, bool loadMissing = false );
+
+    bool loadDefaultImage(
+        OUString const & style,
+        BitmapEx& bitmap);
+
+    /** a crude form of life cycle control (called from DeInitVCL; otherwise,
+     *  if the ImplImageTree singleton were destroyed during exit that would
+     *  be too late for the destructors of the bitmaps in maIconCache)*/
+    void shutDown();
+
+    css::uno::Reference< css::container::XNameAccess > getNameAccess();
+
+private:
+    ImplImageTree(const ImplImageTree&) = delete;
+    ImplImageTree& operator=(const ImplImageTree&) = delete;
+
+    typedef std::unordered_map<OUString, std::pair<bool, BitmapEx>, OUStringHash> IconCache;
+    typedef std::unordered_map<OUString, OUString, OUStringHash> IconLinkHash;
+
+    struct IconSet {
+        OUString maURL;
+        css::uno::Reference<css::container::XNameAccess> maNameAccess;
+        IconCache maIconCache;
+        IconLinkHash maLinkHash;
+
+        IconSet() {}
+        IconSet(const OUString &aURL) : maURL(aURL) {}
+    };
+
+    /// Map between the theme name(s) and the content.
+    typedef std::unordered_map<OUString, IconSet, OUStringHash> StyleIconSet;
+
+    /// Remember all the (used) icon styles and individual icons in them.
+    StyleIconSet maIconSet;
+
+    /// Style used for the current operations; switches switch several times during fallback search.
+    OUString maCurrentStyle;
+
+    bool doLoadImage(
+        OUString const & name, OUString const & style,
+        BitmapEx & bitmap, bool localized);
+
+    bool checkPathAccess();
+
+    void setStyle(OUString const & style );
+
+    void createStyle();
+
+    bool iconCacheLookup( OUString const & name, bool localized, BitmapEx & bitmap );
+
+    bool findImage(std::vector< OUString > const & paths, BitmapEx & bitmap );
+
+    void loadImageLinks();
+
+    void parseLinkFile(std::shared_ptr<SvStream> stream);
+
+    /// Return name of a real .png according to links.txt.
+    OUString const & getRealImageName(OUString const & name);
+
+    /** Return name of the fallback style for the provided one.
+
+        Must not be cyclic :-)  The last theme in the chain returns an empty string.
+    */
+    static OUString fallbackStyle(const OUString &style);
+};
+
+#endif
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */