uic: Add option for absolute Python resource imports

Add option that generates an absolute Python import.

import resources.rc_resources

from a path like

../resources/resources.qrc

assuming the project root is .. .

Add an additional option to specify the import paths, from which
the project root can be determined.

Task-number: PYSIDE-2191
Change-Id: Ib444eb666217b8c010dba0079b0ffe9ddbaa3414
Reviewed-by: Cristian Maureira-Fredes <cristian.maureira-fredes@qt.io>
Reviewed-by: Shyamnath Premnadh <Shyamnath.Premnadh@qt.io>
(cherry picked from commit 814d66d55860a1eb204b804871d579da95eabd8f)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

src/tools/uic/main.cpp

@@ -13,11 +13,42 @@
 #include <qcoreapplication.h>
 #include <qcommandlineoption.h>
 #include <qcommandlineparser.h>
+#include <qfileinfo.h>
 
 QT_BEGIN_NAMESPACE
 
 using namespace Qt::StringLiterals;
 
+static const char pythonPathVar[] = "PYTHONPATH";
+
+// From the Python paths, find the component the UI file is under
+static QString pythonRoot(const QString &pythonPath, const QString &uiFileIn)
+{
+#ifdef Q_OS_WIN
+    static const Qt::CaseSensitivity fsSensitivity = Qt::CaseInsensitive;
+#else
+    static const Qt::CaseSensitivity fsSensitivity = Qt::CaseSensitive;
+#endif
+
+    if (pythonPath.isEmpty() || uiFileIn.isEmpty())
+        return {};
+    const QString uiFile = QFileInfo(uiFileIn).canonicalFilePath();
+    if (uiFile.isEmpty())
+        return {};
+    const auto uiFileSize = uiFile.size();
+    const auto paths = pythonPath.split(QDir::listSeparator(), Qt::SkipEmptyParts);
+    for (const auto &path : paths) {
+        const QString canonicalPath = QFileInfo(path).canonicalFilePath();
+        const auto canonicalPathSize = canonicalPath.size();
+        if (uiFileSize > canonicalPathSize
+            && uiFile.at(canonicalPathSize) == u'/'
+            && uiFile.startsWith(canonicalPath, fsSensitivity)) {
+            return canonicalPath;
+        }
+    }
+    return {};
+}
+
 int runUic(int argc, char *argv[])
 {
     QHashSeed::setDeterministicGlobalSeed();
@@ -90,6 +121,10 @@ int runUic(int argc, char *argv[])
     fromImportsOption.setDescription(u"Python: generate imports relative to '.'"_s);
     parser.addOption(fromImportsOption);
 
+    QCommandLineOption absoluteImportsOption(u"absolute-imports"_s);
+    absoluteImportsOption.setDescription(u"Python: generate absolute imports"_s);
+    parser.addOption(absoluteImportsOption);
+
     // FIXME Qt 7: Flip the default?
     QCommandLineOption rcPrefixOption(u"rc-prefix"_s);
     rcPrefixOption.setDescription(uR"(Python: Generate "rc_file" instead of "file_rc" import)"_s);
@@ -100,6 +135,11 @@ int runUic(int argc, char *argv[])
     useStarImportsOption.setDescription(u"Python: Use * imports"_s);
     parser.addOption(useStarImportsOption);
 
+    QCommandLineOption pythonPathOption(u"python-paths"_s);
+    pythonPathOption.setDescription(u"Python paths for --absolute-imports."_s);
+    pythonPathOption.setValueName(u"pathlist"_s);
+    parser.addOption(pythonPathOption);
+
     parser.addPositionalArgument(u"[uifile]"_s, u"Input file (*.ui), otherwise stdin."_s);
 
     parser.process(app);
@@ -130,10 +170,19 @@ int runUic(int argc, char *argv[])
     }
     language::setLanguage(language);
     if (language == Language::Python) {
-        driver.option().fromImports = parser.isSet(fromImportsOption);
+        if (parser.isSet(fromImportsOption))
+            driver.option().pythonResourceImport = Option::PythonResourceImport::FromDot;
+        else if (parser.isSet(absoluteImportsOption))
+            driver.option().pythonResourceImport = Option::PythonResourceImport::Absolute;
         driver.option().useStarImports = parser.isSet(useStarImportsOption);
         if (parser.isSet(rcPrefixOption))
             driver.option().rcPrefix = 1;
+        QString pythonPaths;
+        if (parser.isSet(pythonPathOption))
+            pythonPaths = parser.value(pythonPathOption);
+        else if (qEnvironmentVariableIsSet(pythonPathVar))
+            pythonPaths = QString::fromUtf8(qgetenv(pythonPathVar));
+        driver.option().pythonRoot = pythonRoot(pythonPaths, inputFile);
     }
 
     if (inputFile.isEmpty()) // reading from stdin

src/tools/uic/option.h

@@ -11,6 +11,12 @@ QT_BEGIN_NAMESPACE
 
 struct Option
 {
+    enum class PythonResourceImport {
+        Default, // "import rc_file"
+        FromDot, // "from . import rc_file"
+        Absolute // "import path.rc_file"
+    };
+
     unsigned int headerProtection : 1;
     unsigned int copyrightHeader : 1;
     unsigned int generateImplemetation : 1;
@@ -20,7 +26,6 @@ struct Option
     unsigned int limitXPM_LineLength : 1;
     unsigned int implicitIncludes: 1;
     unsigned int idBased: 1;
-    unsigned int fromImports: 1;
     unsigned int forceMemberFnPtrConnectionSyntax: 1;
     unsigned int forceStringConnectionSyntax: 1;
     unsigned int useStarImports: 1;
@@ -34,6 +39,9 @@ struct Option
     QString postfix;
     QString translateFunction;
     QString includeFile;
+    QString pythonRoot;
+
+    PythonResourceImport pythonResourceImport = PythonResourceImport::Default;
 
     Option()
         : headerProtection(1),
@@ -45,7 +53,6 @@ struct Option
           limitXPM_LineLength(0),
           implicitIncludes(1),
           idBased(0),
-          fromImports(0),
           forceMemberFnPtrConnectionSyntax(0),
           forceStringConnectionSyntax(0),
           useStarImports(0),

src/tools/uic/python/pythonwriteimports.cpp

@@ -10,6 +10,8 @@
 
 #include <ui4.h>
 
+#include <QtCore/qdir.h>
+#include <QtCore/qfileinfo.h>
 #include <QtCore/qtextstream.h>
 
 #include <algorithm>
@@ -54,23 +56,6 @@ static WriteImports::ClassesPerModule defaultClasses()
     };
 }
 
-// Change the name of a qrc file "dir/foo.qrc" file to the Python
-// module name "foo_rc" according to project conventions.
-static QString pythonResource(QString resource, bool prefix)
-{
-    const qsizetype lastSlash = resource.lastIndexOf(u'/');
-    if (lastSlash != -1)
-        resource.remove(0, lastSlash + 1);
-    if (resource.endsWith(".qrc"_L1)) {
-        resource.chop(4);
-        if (prefix)
-            resource.prepend("rc_"_L1);
-        else
-            resource.append("_rc"_L1);
-    }
-    return resource;
-}
-
 // Helpers for WriteImports::ClassesPerModule maps
 static void insertClass(const QString &module, const QString &className,
                         WriteImports::ClassesPerModule *c)
@@ -143,18 +128,57 @@ void WriteImports::acceptUI(DomUI *node)
         const auto includes = resources->elementInclude();
         for (auto include : includes) {
             if (include->hasAttributeLocation())
-                writeImport(pythonResource(include->attributeLocation(),
+                writeResourceImport(include->attributeLocation());
-                            uic()->option().rcPrefix));
         }
         output << '\n';
     }
 }
 
-void WriteImports::writeImport(const QString &module)
+QString WriteImports::resourceAbsolutePath(QString resource) const
 {
-    if (uic()->option().fromImports)
+    // If we know the project root, generate an absolute Python import
-        uic()->output() << "from  . ";
+    // to the resource. options. pythonRoot is the Python path component
-    uic()->output() << "import " << module << '\n';
+    // under which the UI file is.
+    const auto &options = uic()->option();
+    if (!options.inputFile.isEmpty() && !options.pythonRoot.isEmpty()) {
+        resource = QDir::cleanPath(QFileInfo(options.inputFile).canonicalPath() + u'/' + resource);
+        if (resource.size() > options.pythonRoot.size())
+            resource.remove(0, options.pythonRoot.size() + 1);
+    }
+    // If nothing is known, we assume the directory pointed by "../" is the root
+    while (resource.startsWith(u"../"))
+        resource.remove(0, 3);
+    resource.replace(u'/', u'.');
+    return resource;
+}
+
+void WriteImports::writeResourceImport(const QString &module)
+{
+    const auto &options = uic()->option();
+    auto &str = uic()->output();
+
+    QString resource = QDir::cleanPath(module);
+    if (resource.endsWith(u".qrc"))
+        resource.chop(4);
+    const qsizetype basePos = resource.lastIndexOf(u'/') + 1;
+    // Change the name of a qrc file "dir/foo.qrc" file to the Python
+    // module name "foo_rc" according to project conventions.
+    if (options.rcPrefix)
+        resource.insert(basePos, u"rc_");
+    else
+        resource.append(u"_rc");
+
+    switch (options.pythonResourceImport) {
+    case Option::PythonResourceImport::Default:
+        str << "import " << QStringView{resource}.sliced(basePos) << '\n';
+        break;
+    case Option::PythonResourceImport::FromDot:
+        str << "from . import " << QStringView{resource}.sliced(basePos) << '\n';
+        break;
+    case Option::PythonResourceImport::Absolute:
+        str << "import " << resourceAbsolutePath(resource) << '\n';
+        break;
+    }
 }
 
 void WriteImports::doAdd(const QString &className, const DomCustomWidget *dcw)

src/tools/uic/python/pythonwriteimports.h

@@ -31,7 +31,8 @@ private:
     void addPythonCustomWidget(const QString &className, const DomCustomWidget *dcw);
     bool addQtClass(const QString &className);
     void addEnumBaseClass(const QString &v);
-    void writeImport(const QString &module);
+    void writeResourceImport(const QString &module);
+    QString resourceAbsolutePath(QString resource) const;
 
     QHash<QString, QString> m_classToModule;
     // Module->class (modules sorted)