Windows: Cache the printer capability information the first time

As remote based printers can be slow to query, meaning that it will take
time to check all the capabilities, especially if the QPrinter is
recreated on need. Then the information should be cached and reused if
the printer is deemed to be the same.

Change-Id: If8f9626c0d44113c698b4f61bbd197157932ccbe
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>

2 files changed, 167 insertions, 10 deletions

diff --git a/src/plugins/printsupport/windows/qwindowsprintdevice.cpp b/src/plugins/printsupport/windows/qwindowsprintdevice.cpp
index b1589c0738..300d553628 100644
--- a/src/plugins/printsupport/windows/qwindowsprintdevice.cpp
+++ b/src/plugins/printsupport/windows/qwindowsprintdevice.cpp
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
 ** Copyright (C) 2014 John Layt <jlayt@kde.org>
-** Copyright (C) 2016 The Qt Company Ltd.
+** Copyright (C) 2018 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the plugins of the Qt Toolkit.
@@ -49,6 +49,8 @@
 QT_BEGIN_NAMESPACE
 
 QT_WARNING_DISABLE_GCC("-Wsign-compare")
+typedef QVector<QWindowsPrinterInfo> WindowsPrinterLookup;
+Q_GLOBAL_STATIC(WindowsPrinterLookup, windowsDeviceLookup);
 
 extern qreal qt_pointMultiplier(QPageLayout::Unit unit);
 
@@ -121,15 +123,39 @@ QWindowsPrintDevice::QWindowsPrintDevice(const QString &id)
                 m_makeAndModel = QString::fromWCharArray(info->pDriverName); // TODO Check is not available elsewhere
                 m_isRemote = info->Attributes & PRINTER_ATTRIBUTE_NETWORK;
             }
-            m_supportsMultipleCopies = (DeviceCapabilities((LPWSTR)m_id.utf16(), NULL, DC_COPIES, NULL, NULL) > 1);
-            m_supportsCollateCopies = DeviceCapabilities((LPWSTR)m_id.utf16(), NULL, DC_COLLATE, NULL, NULL);
-            // Min/Max custom size is in tenths of a millimeter
-            const qreal multiplier = qt_pointMultiplier(QPageLayout::Millimeter);
-            DWORD min = DeviceCapabilities((LPWSTR)m_id.utf16(), NULL, DC_MINEXTENT, NULL, NULL);
-            m_minimumPhysicalPageSize = QSize((LOWORD(min) / 10.0) * multiplier, (HIWORD(min) / 10.0) * multiplier);
-            DWORD max = DeviceCapabilities((LPWSTR)m_id.utf16(), NULL, DC_MAXEXTENT, NULL, NULL);
-            m_maximumPhysicalPageSize = QSize((LOWORD(max) / 10.0) * multiplier, (HIWORD(max) / 10.0) * multiplier);
-            m_supportsCustomPageSizes = (m_maximumPhysicalPageSize.width() > 0 && m_maximumPhysicalPageSize.height() > 0);
+            QWindowsPrinterInfo m_info;
+            m_info.m_id = m_id;
+            m_info.m_name = m_name;
+            m_info.m_location = m_location;
+            m_info.m_makeAndModel = m_makeAndModel;
+            m_info.m_isRemote = m_isRemote;
+            m_infoIndex = windowsDeviceLookup()->indexOf(m_info);
+            if (m_infoIndex != -1) {
+                m_info = windowsDeviceLookup()->at(m_infoIndex);
+                m_havePageSizes = m_info.m_havePageSizes;
+                m_pageSizes = m_info.m_pageSizes;
+                m_haveResolutions = m_info.m_haveResolutions;
+                m_resolutions = m_info.m_resolutions;
+                m_haveCopies = m_info.m_haveCopies;
+                m_supportsMultipleCopies = m_info.m_supportsMultipleCopies;
+                m_supportsCollateCopies = m_info.m_supportsCollateCopies;
+                m_haveMinMaxPageSizes = m_info.m_haveMinMaxPageSizes;
+                m_minimumPhysicalPageSize = m_info.m_minimumPhysicalPageSize;
+                m_maximumPhysicalPageSize = m_info.m_maximumPhysicalPageSize;
+                m_supportsCustomPageSizes = m_info.m_supportsCustomPageSizes;
+                m_haveInputSlots = m_info.m_haveInputSlots;
+                m_inputSlots = m_info.m_inputSlots;
+                m_haveOutputBins = m_info.m_haveOutputBins;
+                m_outputBins = m_info.m_outputBins;
+                m_haveDuplexModes = m_info.m_haveDuplexModes;
+                m_duplexModes = m_info.m_duplexModes;
+                m_haveColorModes = m_info.m_haveColorModes;
+                m_colorModes = m_info.m_colorModes;
+                m_infoIndex = windowsDeviceLookup()->indexOf(m_info);
+            } else {
+                windowsDeviceLookup()->append(m_info);
+                m_infoIndex = windowsDeviceLookup()->count() - 1;
+            }
         }
     }
 }
@@ -205,6 +231,9 @@ void QWindowsPrintDevice::loadPageSizes() const
     }
 
     m_havePageSizes = true;
+    QWindowsPrinterInfo *info = windowsDeviceLookup()->data();
+    info[m_infoIndex].m_havePageSizes = true;
+    info[m_infoIndex].m_pageSizes = m_pageSizes;
 }
 
 QPageSize QWindowsPrintDevice::defaultPageSize() const
@@ -297,6 +326,9 @@ void QWindowsPrintDevice::loadResolutions() const
         }
     }
     m_haveResolutions = true;
+    QWindowsPrinterInfo *info = windowsDeviceLookup()->data();
+    info[m_infoIndex].m_haveResolutions = true;
+    info[m_infoIndex].m_resolutions = m_resolutions;
 }
 
 int QWindowsPrintDevice::defaultResolution() const
@@ -340,6 +372,9 @@ void QWindowsPrintDevice::loadInputSlots() const
     }
 
     m_haveInputSlots = true;
+    QWindowsPrinterInfo *info = windowsDeviceLookup()->data();
+    info[m_infoIndex].m_haveInputSlots = true;
+    info[m_infoIndex].m_inputSlots = m_inputSlots;
 }
 
 QPrint::InputSlot QWindowsPrintDevice::defaultInputSlot() const
@@ -367,6 +402,9 @@ void QWindowsPrintDevice::loadOutputBins() const
 {
     m_outputBins.append(QPlatformPrintDevice::defaultOutputBin());
     m_haveOutputBins = true;
+    QWindowsPrinterInfo *info = windowsDeviceLookup()->data();
+    info[m_infoIndex].m_haveOutputBins = true;
+    info[m_infoIndex].m_outputBins = m_outputBins;
 }
 
 void QWindowsPrintDevice::loadDuplexModes() const
@@ -380,6 +418,9 @@ void QWindowsPrintDevice::loadDuplexModes() const
         m_duplexModes.append(QPrint::DuplexShortSide);
     }
     m_haveDuplexModes = true;
+    QWindowsPrinterInfo *info = windowsDeviceLookup()->data();
+    info[m_infoIndex].m_haveDuplexModes = true;
+    info[m_infoIndex].m_duplexModes = m_duplexModes;
 }
 
 QPrint::DuplexMode QWindowsPrintDevice::defaultDuplexMode() const
@@ -407,6 +448,9 @@ void QWindowsPrintDevice::loadColorModes() const
     if (int(color) == 1)
         m_colorModes.append(QPrint::Color);
     m_haveColorModes = true;
+    QWindowsPrinterInfo *info = windowsDeviceLookup()->data();
+    info[m_infoIndex].m_haveColorModes = true;
+    info[m_infoIndex].m_colorModes = m_colorModes;
 }
 
 QPrint::ColorMode QWindowsPrintDevice::defaultColorMode() const
@@ -457,4 +501,68 @@ QString QWindowsPrintDevice::defaultPrintDeviceId()
     return QString::fromWCharArray(name.data());
 }
 
+void QWindowsPrintDevice::loadCopiesSupport() const
+{
+    LPWSTR printerId = const_cast<LPWSTR>(reinterpret_cast<LPCWSTR>(m_id.utf16()));
+    m_supportsMultipleCopies = (DeviceCapabilities(printerId, NULL, DC_COPIES, NULL, NULL) > 1);
+    m_supportsCollateCopies = DeviceCapabilities(printerId, NULL, DC_COLLATE, NULL, NULL);
+    m_haveCopies = true;
+    QWindowsPrinterInfo *info = windowsDeviceLookup()->data();
+    info[m_infoIndex].m_haveCopies = true;
+    info[m_infoIndex].m_supportsMultipleCopies = m_supportsMultipleCopies;
+    info[m_infoIndex].m_supportsCollateCopies = m_supportsCollateCopies;
+}
+
+bool QWindowsPrintDevice::supportsCollateCopies() const
+{
+    if (!m_haveCopies)
+        loadCopiesSupport();
+    return m_supportsCollateCopies;
+}
+
+bool QWindowsPrintDevice::supportsMultipleCopies() const
+{
+    if (!m_haveCopies)
+        loadCopiesSupport();
+    return m_supportsMultipleCopies;
+}
+
+bool QWindowsPrintDevice::supportsCustomPageSizes() const
+{
+    if (!m_haveMinMaxPageSizes)
+        loadMinMaxPageSizes();
+    return m_supportsCustomPageSizes;
+}
+
+QSize QWindowsPrintDevice::minimumPhysicalPageSize() const
+{
+    if (!m_haveMinMaxPageSizes)
+        loadMinMaxPageSizes();
+    return m_minimumPhysicalPageSize;
+}
+
+QSize QWindowsPrintDevice::maximumPhysicalPageSize() const
+{
+    if (!m_haveMinMaxPageSizes)
+        loadMinMaxPageSizes();
+    return m_maximumPhysicalPageSize;
+}
+
+void QWindowsPrintDevice::loadMinMaxPageSizes() const
+{
+    // Min/Max custom size is in tenths of a millimeter
+    const qreal multiplier = qt_pointMultiplier(QPageLayout::Millimeter);
+    LPWSTR printerId = const_cast<LPWSTR>(reinterpret_cast<LPCWSTR>(m_id.utf16()));
+    DWORD min = DeviceCapabilities(printerId, NULL, DC_MINEXTENT, NULL, NULL);
+    m_minimumPhysicalPageSize = QSize((LOWORD(min) / 10.0) * multiplier, (HIWORD(min) / 10.0) * multiplier);
+    DWORD max = DeviceCapabilities(printerId, NULL, DC_MAXEXTENT, NULL, NULL);
+    m_maximumPhysicalPageSize = QSize((LOWORD(max) / 10.0) * multiplier, (HIWORD(max) / 10.0) * multiplier);
+    m_supportsCustomPageSizes = (m_maximumPhysicalPageSize.width() > 0 && m_maximumPhysicalPageSize.height() > 0);
+    m_haveMinMaxPageSizes = true;
+    QWindowsPrinterInfo *info = windowsDeviceLookup()->data();
+    info[m_infoIndex].m_haveCopies = true;
+    info[m_infoIndex].m_supportsMultipleCopies = m_supportsMultipleCopies;
+    info[m_infoIndex].m_supportsCollateCopies = m_supportsCollateCopies;
+}
+
 QT_END_NAMESPACE
diff --git a/src/plugins/printsupport/windows/qwindowsprintdevice.h b/src/plugins/printsupport/windows/qwindowsprintdevice.h
index 6b51ee8785..9f6d31da5f 100644
--- a/src/plugins/printsupport/windows/qwindowsprintdevice.h
+++ b/src/plugins/printsupport/windows/qwindowsprintdevice.h
@@ -1,6 +1,7 @@
 /****************************************************************************
 **
 ** Copyright (C) 2014 John Layt <jlayt@kde.org>
+** Copyright (C) 2018 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the plugins of the Qt Toolkit.
@@ -57,6 +58,43 @@
 
 QT_BEGIN_NAMESPACE
 
+class QWindowsPrinterInfo
+{
+public:
+    bool operator==(const QWindowsPrinterInfo &other) const
+    {
+        // We only need to check if these are the same for matching up
+        return m_id == other.m_id && m_name == other.m_name &&
+               m_location == other.m_location &&
+               m_makeAndModel == other.m_makeAndModel &&
+               m_isRemote == other.m_isRemote;
+    }
+    QString m_id;
+    QString m_name;
+    QString m_location;
+    QString m_makeAndModel;
+    QList<QPageSize> m_pageSizes;
+    QList<int> m_resolutions;
+    QVector<QPrint::InputSlot> m_inputSlots;
+    QVector<QPrint::OutputBin> m_outputBins;
+    QVector<QPrint::DuplexMode> m_duplexModes;
+    QVector<QPrint::ColorMode> m_colorModes;
+    QSize m_minimumPhysicalPageSize;
+    QSize m_maximumPhysicalPageSize;
+    bool m_isRemote = false;
+    bool m_havePageSizes = false;
+    bool m_haveResolutions = false;
+    bool m_haveCopies = false;
+    bool m_supportsMultipleCopies = false;
+    bool m_supportsCollateCopies = false;
+    bool m_haveMinMaxPageSizes = false;
+    bool m_supportsCustomPageSizes = false;
+    bool m_haveInputSlots = false;
+    bool m_haveOutputBins = false;
+    bool m_haveDuplexModes = false;
+    bool m_haveColorModes = false;
+};
+
 class QWindowsPrintDevice : public QPlatformPrintDevice
 {
 public:
@@ -85,6 +123,12 @@ public:
     static QStringList availablePrintDeviceIds();
     static QString defaultPrintDeviceId();
 
+    bool supportsCollateCopies() const override;
+    bool supportsMultipleCopies() const override;
+    bool supportsCustomPageSizes() const override;
+    QSize minimumPhysicalPageSize() const override;
+    QSize maximumPhysicalPageSize() const override;
+
 protected:
     void loadPageSizes() const override;
     void loadResolutions() const override;
@@ -92,9 +136,14 @@ protected:
     void loadOutputBins() const override;
     void loadDuplexModes() const override;
     void loadColorModes() const override;
+    void loadCopiesSupport() const;
+    void loadMinMaxPageSizes() const;
 
 private:
     HANDLE m_hPrinter;
+    mutable bool m_haveCopies;
+    mutable bool m_haveMinMaxPageSizes;
+    int m_infoIndex;
 };
 
 QT_END_NAMESPACE