Qt: Split the filter dropdown arrow icon into dark and light versions.

The capture and display filter widgets set their dropdown arrow icons
using CSS, which means we can't use a template icon without a
significant amount of hackery. This is the only instance where we set an
icon using CSS, so split it into dark and light versions and use them as
appropriate.

Ping-Bug: 15511
Change-Id: I699ddc327d8eb109129e60bcb5036b14e6e34414
Reviewed-on: https://code.wireshark.org/review/33696
Reviewed-by: Gerald Combs <gerald@wireshark.org>
Petri-Dish: Gerald Combs <gerald@wireshark.org>
Tested-by: Petri Dish Buildbot
Reviewed-by: Alexis La Goutte <alexis.lagoutte@gmail.com>

4 files changed, 98 insertions, 62 deletions

diff --git a/ui/qt/widgets/capture_filter_combo.cpp b/ui/qt/widgets/capture_filter_combo.cpp
index e869d6f924..7525d2130c 100644
--- a/ui/qt/widgets/capture_filter_combo.cpp
+++ b/ui/qt/widgets/capture_filter_combo.cpp
@@ -16,6 +16,7 @@
 #include <epan/prefs.h>
 
 #include <ui/qt/widgets/capture_filter_combo.h>
+#include <ui/qt/utils/color_utils.h>
 #include "wireshark_application.h"
 
 CaptureFilterCombo::CaptureFilterCombo(QWidget *parent, bool plain) :
@@ -34,35 +35,7 @@ CaptureFilterCombo::CaptureFilterCombo(QWidget *parent, bool plain) :
     setSizePolicy(QSizePolicy::MinimumExpanding, sizePolicy().verticalPolicy());
     setInsertPolicy(QComboBox::NoInsert);
     setAccessibleName(tr("Capture filter selector"));
-    setStyleSheet(
-            "QComboBox {"
-#ifdef Q_OS_MAC
-            "  border: 1px solid gray;"
-#else
-            "  border: 1px solid palette(shadow);"
-#endif
-            "  border-radius: 3px;"
-            "  padding: 0px 0px 0px 0px;"
-            "  margin-left: 0px;"
-            "  min-width: 20em;"
-            " }"
-
-            "QComboBox::drop-down {"
-            "  subcontrol-origin: padding;"
-            "  subcontrol-position: top right;"
-            "  width: 16px;"
-            "  border-left-width: 0px;"
-            " }"
-
-            "QComboBox::down-arrow {"
-            "  image: url(:/stock_icons/14x14/x-filter-dropdown.png);"
-            " }"
-
-            "QComboBox::down-arrow:on { /* shift the arrow when popup is open */"
-            "  top: 1px;"
-            "  left: 1px;"
-            "}"
-            );
+    updateStyleSheet();
 
     connect(this, &CaptureFilterCombo::interfacesChanged, cf_edit_,
             static_cast<void (CaptureFilterEdit::*)()>(&CaptureFilterEdit::checkFilter));
@@ -93,6 +66,54 @@ void CaptureFilterCombo::writeRecent(FILE *rf)
     }
 }
 
+bool CaptureFilterCombo::event(QEvent *event)
+{
+    switch (event->type()) {
+    case QEvent::PaletteChange:
+        updateStyleSheet();
+        break;
+    default:
+        break;
+    }
+    return QComboBox::event(event);
+}
+
+void CaptureFilterCombo::updateStyleSheet()
+{
+    const char *display_mode = ColorUtils::themeIsDark() ? "dark" : "light";
+
+    QString ss = QString(
+                "QComboBox {"
+#ifdef Q_OS_MAC
+                "  border: 1px solid gray;"
+#else
+                "  border: 1px solid palette(shadow);"
+#endif
+                "  border-radius: 3px;"
+                "  padding: 0px 0px 0px 0px;"
+                "  margin-left: 0px;"
+                "  min-width: 20em;"
+                " }"
+
+                "QComboBox::drop-down {"
+                "  subcontrol-origin: padding;"
+                "  subcontrol-position: top right;"
+                "  width: 16px;"
+                "  border-left-width: 0px;"
+                " }"
+
+                "QComboBox::down-arrow {"
+                "  image: url(:/stock_icons/14x14/x-filter-dropdown.%1.png);"
+                " }"
+
+                "QComboBox::down-arrow:on { /* shift the arrow when popup is open */"
+                "  top: 1px;"
+                "  left: 1px;"
+                "}"
+                ).arg(display_mode);
+    setStyleSheet(ss);
+}
+
 void CaptureFilterCombo::saveAndRebuildFilterList()
 {
     if (!currentText().isEmpty()) {
diff --git a/ui/qt/widgets/capture_filter_combo.h b/ui/qt/widgets/capture_filter_combo.h
index ba6baf62e4..a0c4edb66d 100644
--- a/ui/qt/widgets/capture_filter_combo.h
+++ b/ui/qt/widgets/capture_filter_combo.h
@@ -31,9 +31,11 @@ signals:
     void captureFilterSyntaxChanged(bool valid);
     void startCapture();
 
-public slots:
+protected:
+    virtual bool event(QEvent *event);
 
 private:
+    void updateStyleSheet();
     CaptureFilterEdit *cf_edit_;
 
 private slots:
diff --git a/ui/qt/widgets/display_filter_combo.cpp b/ui/qt/widgets/display_filter_combo.cpp
index 6f2cf71f20..ba2298d14f 100644
--- a/ui/qt/widgets/display_filter_combo.cpp
+++ b/ui/qt/widgets/display_filter_combo.cpp
@@ -20,6 +20,7 @@
 
 #include <ui/qt/widgets/display_filter_edit.h>
 #include <ui/qt/widgets/display_filter_combo.h>
+#include <ui/qt/utils/color_utils.h>
 #include "wireshark_application.h"
 
 // If we ever add support for multiple windows this will need to be replaced.
@@ -37,36 +38,8 @@ DisplayFilterCombo::DisplayFilterCombo(QWidget *parent) :
     // Default is Preferred.
     setSizePolicy(QSizePolicy::MinimumExpanding, sizePolicy().verticalPolicy());
     setAccessibleName(tr("Display filter selector"));
-    cur_display_filter_combo = this;
-    setStyleSheet(
-            "QComboBox {"
-#ifdef Q_OS_MAC
-            "  border: 1px solid gray;"
-#else
-            "  border: 1px solid palette(shadow);"
-#endif
-            "  border-radius: 3px;"
-            "  padding: 0px 0px 0px 0px;"
-            "  margin-left: 0px;"
-            "  min-width: 20em;"
-            " }"
-
-            "QComboBox::drop-down {"
-            "  subcontrol-origin: padding;"
-            "  subcontrol-position: top right;"
-            "  width: 14px;"
-            "  border-left-width: 0px;"
-            " }"
-
-            "QComboBox::down-arrow {"
-            "  image: url(:/stock_icons/14x14/x-filter-dropdown.png);"
-            " }"
-
-            "QComboBox::down-arrow:on { /* shift the arrow when popup is open */"
-            "  top: 1px;"
-            "  left: 1px;"
-            "}"
-            );
+    cur_display_filter_combo = this;    
+    updateStyleSheet();
     setToolTip(tr("Select from previously used filters."));
 
     connect(wsApp, &WiresharkApplication::preferencesChanged, this, &DisplayFilterCombo::updateMaxCount);
@@ -105,12 +78,51 @@ bool DisplayFilterCombo::event(QEvent *event)
         }
         break;
     }
+    case QEvent::PaletteChange:
+        updateStyleSheet();
+        break;
     default:
         break;
     }
     return QComboBox::event(event);
 }
 
+void DisplayFilterCombo::updateStyleSheet()
+{
+    const char *display_mode = ColorUtils::themeIsDark() ? "dark" : "light";
+
+    QString ss = QString(
+                "QComboBox {"
+#ifdef Q_OS_MAC
+                "  border: 1px solid gray;"
+#else
+                "  border: 1px solid palette(shadow);"
+#endif
+                "  border-radius: 3px;"
+                "  padding: 0px 0px 0px 0px;"
+                "  margin-left: 0px;"
+                "  min-width: 20em;"
+                " }"
+
+                "QComboBox::drop-down {"
+                "  subcontrol-origin: padding;"
+                "  subcontrol-position: top right;"
+                "  width: 14px;"
+                "  border-left-width: 0px;"
+                " }"
+
+                "QComboBox::down-arrow {"
+                "  image: url(:/stock_icons/14x14/x-filter-dropdown.%1.png);"
+                " }"
+
+                "QComboBox::down-arrow:on { /* shift the arrow when popup is open */"
+                "  top: 1px;"
+                "  left: 1px;"
+                "}"
+                ).arg(display_mode);
+    setStyleSheet(ss);
+}
+
 bool DisplayFilterCombo::checkDisplayFilter()
 {
     DisplayFilterEdit *df_edit = qobject_cast<DisplayFilterEdit *>(lineEdit());
diff --git a/ui/qt/widgets/display_filter_combo.h b/ui/qt/widgets/display_filter_combo.h
index 891e7544c1..8ff17174d9 100644
--- a/ui/qt/widgets/display_filter_combo.h
+++ b/ui/qt/widgets/display_filter_combo.h
@@ -21,11 +21,12 @@ public:
     bool addRecentCapture(const char *filter);
     void writeRecent(FILE *rf);
 
-signals:
-
 protected:
     virtual bool event(QEvent *event);
 
+private:
+    void updateStyleSheet();
+
 public slots:
     bool checkDisplayFilter();
     void applyDisplayFilter();