make path inputs support drag/dropping files onto them to add the path quickly. fixes #1033

src/frontend/qt_sdl/AudioSettingsDialog.ui

@@ -62,7 +62,7 @@
      </property>
      <layout class="QGridLayout" name="gridLayout">
       <item row="3" column="1">
-       <widget class="QLineEdit" name="txtMicWavPath">
+       <widget class="QPathInput" name="txtMicWavPath">
         <property name="minimumSize">
          <size>
           <width>290</width>
@@ -136,6 +136,13 @@
    </item>
   </layout>
  </widget>
+ <customwidgets>
+  <customwidget>
+   <class>QPathInput</class>
+   <extends>QLineEdit</extends>
+   <header>QPathInput.h</header>
+  </customwidget>
+ </customwidgets>
  <resources/>
  <connections>
   <connection>

src/frontend/qt_sdl/CMakeLists.txt

@@ -18,6 +18,7 @@ SET(SOURCES_QT_SDL
     font.h
     Platform.cpp
     PlatformConfig.cpp
+	QPathInput.h
     
     ArchiveUtil.h
     ArchiveUtil.cpp

src/frontend/qt_sdl/EmuSettingsDialog.ui

@@ -90,14 +90,14 @@
       </attribute>
       <layout class="QGridLayout" name="gridLayout">
        <item row="1" column="1">
-        <widget class="QLineEdit" name="txtBIOS7Path">
+        <widget class="QPathInput" name="txtBIOS7Path">
          <property name="whatsThis">
           <string>&lt;html&gt;&lt;head/&gt;&lt;body&gt;&lt;p&gt;DS-mode ARM7 BIOS&lt;/p&gt;&lt;p&gt;Size should be 16 KB&lt;/p&gt;&lt;/body&gt;&lt;/html&gt;</string>
          </property>
         </widget>
        </item>
        <item row="2" column="1">
-        <widget class="QLineEdit" name="txtFirmwarePath">
+        <widget class="QPathInput" name="txtFirmwarePath">
          <property name="whatsThis">
           <string>&lt;html&gt;&lt;head/&gt;&lt;body&gt;&lt;p&gt;DS-mode firmware&lt;/p&gt;&lt;p&gt;&lt;br/&gt;&lt;/p&gt;&lt;p&gt;Possible firmwares:&lt;/p&gt;&lt;p&gt;* 128 KB: DS-mode firmware from a DSi or 3DS. Not bootable.&lt;/p&gt;&lt;p&gt;* 256 KB: regular DS firmware.&lt;/p&gt;&lt;p&gt;* 512 KB: iQue DS firmware.&lt;/p&gt;&lt;/body&gt;&lt;/html&gt;</string>
          </property>
@@ -155,7 +155,7 @@
         </widget>
        </item>
        <item row="0" column="1">
-        <widget class="QLineEdit" name="txtBIOS9Path">
+        <widget class="QPathInput" name="txtBIOS9Path">
          <property name="sizePolicy">
           <sizepolicy hsizetype="Expanding" vsizetype="Fixed">
            <horstretch>0</horstretch>
@@ -197,7 +197,7 @@
       </attribute>
       <layout class="QGridLayout" name="gridLayout_2">
        <item row="1" column="1">
-        <widget class="QLineEdit" name="txtDSiBIOS7Path">
+        <widget class="QPathInput" name="txtDSiBIOS7Path">
          <property name="whatsThis">
           <string>&lt;html&gt;&lt;head/&gt;&lt;body&gt;&lt;p&gt;DSi-mode ARM7 BIOS&lt;/p&gt;&lt;p&gt;&lt;br/&gt;&lt;/p&gt;&lt;p&gt;Size should be 64 KB&lt;/p&gt;&lt;/body&gt;&lt;/html&gt;</string>
          </property>
@@ -239,7 +239,7 @@
         </widget>
        </item>
        <item row="3" column="1">
-        <widget class="QLineEdit" name="txtDSiNANDPath">
+        <widget class="QPathInput" name="txtDSiNANDPath">
          <property name="whatsThis">
           <string>&lt;html&gt;&lt;head/&gt;&lt;body&gt;&lt;p&gt;DSi NAND dump&lt;/p&gt;&lt;p&gt;&lt;br/&gt;&lt;/p&gt;&lt;p&gt;Should have 'nocash footer' at the end&lt;/p&gt;&lt;/body&gt;&lt;/html&gt;</string>
          </property>
@@ -260,7 +260,7 @@
         </widget>
        </item>
        <item row="0" column="1">
-        <widget class="QLineEdit" name="txtDSiBIOS9Path">
+        <widget class="QPathInput" name="txtDSiBIOS9Path">
          <property name="sizePolicy">
           <sizepolicy hsizetype="Expanding" vsizetype="Fixed">
            <horstretch>0</horstretch>
@@ -287,14 +287,14 @@
         </widget>
        </item>
        <item row="2" column="1">
-        <widget class="QLineEdit" name="txtDSiFirmwarePath">
+        <widget class="QPathInput" name="txtDSiFirmwarePath">
          <property name="whatsThis">
           <string>&lt;html&gt;&lt;head/&gt;&lt;body&gt;&lt;p&gt;DSi-mode firmware (used for DS-mode backwards compatibility)&lt;/p&gt;&lt;p&gt;&lt;br/&gt;&lt;/p&gt;&lt;p&gt;Size should be 128 KB&lt;/p&gt;&lt;/body&gt;&lt;/html&gt;</string>
          </property>
         </widget>
        </item>
        <item row="5" column="1">
-        <widget class="QLineEdit" name="txtDSiSDPath">
+        <widget class="QPathInput" name="txtDSiSDPath">
          <property name="whatsThis">
           <string>&lt;html&gt;&lt;head/&gt;&lt;body&gt;&lt;p&gt;SD image file for emulating the DSi's SD card&lt;/p&gt;&lt;/body&gt;&lt;/html&gt;</string>
          </property>
@@ -410,7 +410,7 @@
         </widget>
        </item>
        <item row="1" column="1">
-        <widget class="QLineEdit" name="txtDLDISDPath"/>
+        <widget class="QPathInput" name="txtDLDISDPath"/>
        </item>
        <item row="1" column="0">
         <widget class="QLabel" name="label_11">
@@ -448,6 +448,13 @@
    </item>
   </layout>
  </widget>
+ <customwidgets>
+  <customwidget>
+   <class>QPathInput</class>
+   <extends>QLineEdit</extends>
+   <header>QPathInput.h</header>
+  </customwidget>
+ </customwidgets>
  <tabstops>
   <tabstop>cbxConsoleType</tabstop>
   <tabstop>chkDirectBoot</tabstop>

src/frontend/qt_sdl/QPathInput.h

@@ -0,0 +1,66 @@
+/*
+    Copyright 2016-2021 Arisotura
+
+    This file is part of melonDS.
+
+    melonDS is free software: you can redistribute it and/or modify it under
+    the terms of the GNU General Public License as published by the Free
+    Software Foundation, either version 3 of the License, or (at your option)
+    any later version.
+
+    melonDS is distributed in the hope that it will be useful, but WITHOUT ANY
+    WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+    FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License along
+    with melonDS. If not, see http://www.gnu.org/licenses/.
+*/
+
+#ifndef QPATHINPUT_H
+#define QPATHINPUT_H
+
+#include <QLineEdit>
+#include <QDragEnterEvent>
+#include <QDropEvent>
+#include <QMimeData>
+
+class QPathInput : public QLineEdit
+{
+    Q_OBJECT
+
+public:
+    QPathInput(QWidget* parent = nullptr) : QLineEdit(parent)
+    {
+        setAcceptDrops(true);
+    }
+
+    ~QPathInput()
+    {
+    }
+
+protected:
+    void dragEnterEvent(QDragEnterEvent* event) override
+    {
+        if (!event->mimeData()->hasUrls()) return QLineEdit::dragEnterEvent(event);
+
+        QList<QUrl> urls = event->mimeData()->urls();
+        if (urls.count() > 1) return QLineEdit::dragEnterEvent(event);
+
+        QString filename = urls.at(0).toLocalFile();
+
+        event->acceptProposedAction();
+    }
+
+    void dropEvent(QDropEvent* event) override
+    {
+        if (!event->mimeData()->hasUrls()) return QLineEdit::dropEvent(event);
+
+        QList<QUrl> urls = event->mimeData()->urls();
+        if (urls.count() > 1) return QLineEdit::dropEvent(event);
+
+        QString filename = urls.at(0).toLocalFile();
+        setText(filename);
+    }
+};
+
+#endif // QPATHINPUT_H