cppeditor: add resource preview hover handler class

This adds a hover handler which will preview images
from within project resource.

Change-Id: I88bcb56a977e41ed4dc5bfe165e2c80d4396a21f
Reviewed-by: André Hartmann <aha_1980@gmx.de>
Reviewed-by: David Schulz <david.schulz@qt.io>
Reviewed-by: Orgad Shaneh <orgads@gmail.com>

src/plugins/cppeditor/cppeditor.pro

@@ -29,7 +29,8 @@ HEADERS += \
     cpptypehierarchy.h \
     cppuseselectionsupdater.h \
     cppvirtualfunctionassistprovider.h \
-    cppvirtualfunctionproposalitem.h
+    cppvirtualfunctionproposalitem.h \
+    resourcepreviewhoverhandler.h
 
 SOURCES += \
     cppautocompleter.cpp \
@@ -56,7 +57,8 @@ SOURCES += \
     cpptypehierarchy.cpp \
     cppuseselectionsupdater.cpp \
     cppvirtualfunctionassistprovider.cpp \
-    cppvirtualfunctionproposalitem.cpp
+    cppvirtualfunctionproposalitem.cpp \
+    resourcepreviewhoverhandler.cpp
 
 FORMS += \
     cpppreprocessordialog.ui \

src/plugins/cppeditor/cppeditor.qbs

@@ -50,6 +50,7 @@ QtcPlugin {
         "cppuseselectionsupdater.cpp", "cppuseselectionsupdater.h",
         "cppvirtualfunctionassistprovider.cpp", "cppvirtualfunctionassistprovider.h",
         "cppvirtualfunctionproposalitem.cpp", "cppvirtualfunctionproposalitem.h",
+        "resoucepreviewhoverhandler.cpp", "resoucepreviewhoverhandler.h",
     ]
 
     Group {

src/plugins/cppeditor/cppeditorplugin.cpp

@@ -38,6 +38,7 @@
 #include "cppquickfixes.h"
 #include "cppsnippetprovider.h"
 #include "cpptypehierarchy.h"
+#include "resourcepreviewhoverhandler.h"
 
 #include <coreplugin/editormanager/editormanager.h>
 
@@ -106,6 +107,7 @@ public:
 
         addHoverHandler(new CppHoverHandler);
         addHoverHandler(new ColorPreviewHoverHandler);
+        addHoverHandler(new ResourcePreviewHoverHandler);
     }
 };
 

src/plugins/cppeditor/resourcepreviewhoverhandler.cpp

@@ -0,0 +1,209 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 Marc Reilly <marc.reilly+qtc@gmail.com>
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of Qt Creator.
+**
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 as published by the Free Software
+** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+****************************************************************************/
+
+#include "resourcepreviewhoverhandler.h"
+
+#include <coreplugin/icore.h>
+#include <utils/tooltip/tooltip.h>
+#include <utils/fileutils.h>
+#include <utils/qtcassert.h>
+#include <utils/mimetypes/mimedatabase.h>
+#include <projectexplorer/projecttree.h>
+#include <projectexplorer/project.h>
+#include <texteditor/texteditor.h>
+
+#include <QPoint>
+#include <QTextBlock>
+
+using namespace Core;
+using namespace TextEditor;
+
+namespace CppEditor {
+namespace Internal {
+
+/*
+ * finds a quoted sub-string around the pos in the given string
+ *
+ * note: the returned string includes the quotes.
+ */
+static QString extractQuotedString(const QString &s, int pos)
+{
+    if (s.length() < 2 || pos < 0 || pos >= s.length())
+        return QString();
+
+    const int firstQuote = s.lastIndexOf('"', pos);
+    if (firstQuote >= 0) {
+        int endQuote = s.indexOf('"', firstQuote + 1);
+        if (endQuote > firstQuote)
+            return s.mid(firstQuote, endQuote - firstQuote);
+    }
+
+    return QString();
+}
+
+static QString makeResourcePath(const QStringList &prefixList, const QString &file)
+{
+    QTC_ASSERT(!prefixList.isEmpty(), return QString());
+
+    const QChar sep = '/';
+    auto prefix = prefixList.join(sep);
+    if (prefix == sep)
+        return prefix + file;
+
+    return prefix + sep + file;
+}
+
+/*
+ * tries to match a resource within a given .qrc file, including by alias
+ *
+ * note: resource name should not have any semi-colon in front of it
+ */
+static QString findResourceInFile(const QString &resName, const QString &filePathName)
+{
+    Utils::FileReader reader;
+    if (!reader.fetch(filePathName))
+        return QString();
+
+    const QByteArray contents = reader.data();
+    QXmlStreamReader xmlr(contents);
+
+    QStringList prefixStack;
+
+    while (!xmlr.atEnd() && !xmlr.hasError()) {
+        const QXmlStreamReader::TokenType token = xmlr.readNext();
+        if (token == QXmlStreamReader::StartElement) {
+            if (xmlr.name() == "qresource") {
+                const QXmlStreamAttributes sa = xmlr.attributes();
+                const QString prefixName = sa.value("prefix").toString();
+                if (!prefixName.isEmpty())
+                    prefixStack.push_back(prefixName);
+            } else if (xmlr.name() == "file") {
+                const QXmlStreamAttributes sa = xmlr.attributes();
+                const QString aliasName = sa.value("alias").toString();
+                const QString fileName = xmlr.readElementText();
+
+                if (!aliasName.isEmpty()) {
+                    const QString fullAliasName = makeResourcePath(prefixStack, aliasName);
+                    if (resName == fullAliasName)
+                        return fileName;
+                }
+
+                const QString fullResName = makeResourcePath(prefixStack, fileName);
+                if (resName == fullResName)
+                    return fileName;
+            }
+        } else if (token == QXmlStreamReader::EndElement) {
+            if (xmlr.name() == "qresource") {
+                if (!prefixStack.isEmpty())
+                    prefixStack.pop_back();
+            }
+        }
+    }
+
+    return QString();
+}
+
+/*
+ * A more efficient way to do this would be to parse the relevant project files
+ * before hand, or cache them as we go - but this works well enough so far.
+ */
+static QString findResourceInProject(const QString &resName)
+{
+    QString s = resName;
+    s.remove('"');
+
+    if (s.startsWith(":/"))
+        s.remove(0, 1);
+    else if (s.startsWith("qrc://"))
+        s.remove(0, 5);
+    else
+        return QString();
+
+    if (auto *project = ProjectExplorer::ProjectTree::currentProject()) {
+        const QStringList files = project->files(ProjectExplorer::Project::AllFiles);
+        for (const QString &file : files) {
+            if (!file.endsWith(".qrc"))
+                continue;
+            const QFileInfo fi(file);
+            if (!fi.isReadable())
+                continue;
+            const QString fileName = findResourceInFile(s, file);
+            if (fileName.isEmpty())
+                continue;
+
+            QString ret = fi.absolutePath();
+            if (!ret.endsWith('/'))
+                ret.append('/');
+            ret.append(fileName);
+            return ret;
+        }
+    }
+
+    return QString();
+}
+
+void ResourcePreviewHoverHandler::identifyMatch(TextEditorWidget *editorWidget, int pos)
+{
+    if (editorWidget->extraSelectionTooltip(pos).isEmpty()) {
+        const QTextBlock tb = editorWidget->document()->findBlock(pos);
+        const int tbpos = pos - tb.position();
+        const QString tbtext = tb.text();
+
+        const QString resPath = extractQuotedString(tbtext, tbpos);
+        m_resPath = findResourceInProject(resPath);
+
+        setPriority(m_resPath.isEmpty() ? Priority_None : Priority_Diagnostic + 1);
+    }
+}
+
+void ResourcePreviewHoverHandler::operateTooltip(TextEditorWidget *editorWidget, const QPoint &point)
+{
+    const QString tt = makeTooltip();
+    if (!tt.isEmpty())
+        Utils::ToolTip::show(point, tt, editorWidget);
+    else
+        Utils::ToolTip::hide();
+}
+
+QString ResourcePreviewHoverHandler::makeTooltip() const
+{
+    if (m_resPath.isEmpty())
+        return QString();
+
+    QString ret;
+
+    Utils::MimeDatabase mdb;
+    const Utils::MimeType mimeType = mdb.mimeTypeForFile(m_resPath);
+    if (mimeType.isValid()) {
+        if (mimeType.name().startsWith("image", Qt::CaseInsensitive))
+            ret += QString("<img src=\"file:///%1\" /><br/>").arg(m_resPath);
+
+        ret += QString("<a href=\"file:///%1\">%2</a>").arg(m_resPath).arg(m_resPath);
+    }
+    return ret;
+}
+
+} // namespace Internal
+} // namespace CppEditor

src/plugins/cppeditor/resourcepreviewhoverhandler.h

@@ -0,0 +1,50 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 Marc Reilly <marc.reilly+qtc@gmail.com>
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of Qt Creator.
+**
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 as published by the Free Software
+** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+****************************************************************************/
+
+#pragma once
+
+#include <texteditor/basehoverhandler.h>
+
+#include <QString>
+
+namespace CppEditor {
+namespace Internal {
+
+class ResourcePreviewHoverHandler : public TextEditor::BaseHoverHandler
+{
+public:
+
+private:
+    void identifyMatch(TextEditor::TextEditorWidget *editorWidget, int pos) override;
+    void operateTooltip(TextEditor::TextEditorWidget *editorWidget, const QPoint &point) override;
+
+private:
+    QString makeTooltip() const;
+
+    QString m_resPath;
+};
+
+} // namespace Internal
+} // namespace CppEditor