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>

1 files changed, 118 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