Refactor icon lists heavily

* Icon list now uses a filesystem watcher for updates
* Icon folder is user-customizable
* All the little details. ALL OF THEM.

19 files changed, 616 insertions, 306 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 555890bb..62fa2c09 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -372,8 +372,6 @@ logic/LegacyFTBInstance.cpp
 # Lists
 logic/lists/InstanceList.h
 logic/lists/InstanceList.cpp
-logic/lists/IconList.h
-logic/lists/IconList.cpp
 logic/lists/BaseVersionList.h
 logic/lists/BaseVersionList.cpp
 logic/lists/MinecraftVersionList.h
@@ -385,6 +383,13 @@ logic/lists/ForgeVersionList.cpp
 logic/lists/JavaVersionList.h
 logic/lists/JavaVersionList.cpp
 
+# Icons
+logic/icons/MMCIcon.h
+logic/icons/MMCIcon.cpp
+logic/icons/IconList.h
+logic/icons/IconList.cpp
+
+
 # misc model/view
 logic/EnabledItemFilter.h
 logic/EnabledItemFilter.cpp
diff --git a/MultiMC.cpp b/MultiMC.cpp
index 865d0cf1..fe83fbd1 100644
--- a/MultiMC.cpp
+++ b/MultiMC.cpp
@@ -13,7 +13,7 @@
 #include "gui/dialogs/VersionSelectDialog.h"
 #include "logic/lists/InstanceList.h"
 #include "logic/auth/MojangAccountList.h"
-#include "logic/lists/IconList.h"
+#include "logic/icons/IconList.h"
 #include "logic/lists/LwjglVersionList.h"
 #include "logic/lists/MinecraftVersionList.h"
 #include "logic/lists/ForgeVersionList.h"
@@ -382,6 +382,7 @@ void MultiMC::initGlobalSettings()
 	m_settings->registerSetting(new Setting("InstanceDir", "instances"));
 	m_settings->registerSetting(new Setting("CentralModsDir", "mods"));
 	m_settings->registerSetting(new Setting("LWJGLDir", "lwjgl"));
+	m_settings->registerSetting(new Setting("IconsDir", "icons"));
 
 	// Editors
 	m_settings->registerSetting(new Setting("JsonEditor", QString()));
@@ -420,15 +421,6 @@ void MultiMC::initGlobalSettings()
 	m_settings->registerSetting(new Setting("InstSortMode", "Name"));
 	m_settings->registerSetting(new Setting("SelectedInstance", QString()));
 
-	// Persistent value for the client ID
-	m_settings->registerSetting(new Setting("YggdrasilClientToken", ""));
-	QString currentYggID = m_settings->get("YggdrasilClientToken").toString();
-	if (currentYggID.isEmpty())
-	{
-		QUuid uuid = QUuid::createUuid();
-		m_settings->set("YggdrasilClientToken", uuid.toString());
-	}
-
 	// Window state and geometry
 	m_settings->registerSetting(new Setting("MainWindowState", ""));
 	m_settings->registerSetting(new Setting("MainWindowGeometry", ""));
diff --git a/gui/MainWindow.cpp b/gui/MainWindow.cpp
index d16226eb..2ba0d509 100644
--- a/gui/MainWindow.cpp
+++ b/gui/MainWindow.cpp
@@ -66,7 +66,7 @@
 #include "logic/lists/InstanceList.h"
 #include "logic/lists/MinecraftVersionList.h"
 #include "logic/lists/LwjglVersionList.h"
-#include "logic/lists/IconList.h"
+#include "logic/icons/IconList.h"
 #include "logic/lists/JavaVersionList.h"
 
 #include "logic/auth/flows/AuthenticateTask.h"
@@ -165,6 +165,10 @@ MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent), ui(new Ui::MainWi
 	connect(view->selectionModel(),
 			SIGNAL(currentChanged(const QModelIndex &, const QModelIndex &)), this,
 			SLOT(instanceChanged(const QModelIndex &, const QModelIndex &)));
+
+	// track icon changes and update the toolbar!
+	connect(MMC->icons().get(), SIGNAL(iconUpdated(QString)), SLOT(iconUpdated(QString)));
+
 	// model reset -> selection is invalid. All the instance pointers are wrong.
 	// FIXME: stop using POINTERS everywhere
 	connect(MMC->instances().get(), SIGNAL(dataIsInvalid()), SLOT(selectionBad()));
@@ -635,11 +639,27 @@ void MainWindow::on_actionChangeInstIcon_triggered()
 	if (dlg.result() == QDialog::Accepted)
 	{
 		m_selectedInstance->setIconKey(dlg.selectedIconKey);
+		/*
 		auto ico = MMC->icons()->getIcon(dlg.selectedIconKey);
 		ui->actionChangeInstIcon->setIcon(ico);
+		*/
+	}
+}
+
+void MainWindow::iconUpdated(QString icon)
+{
+	if(icon == m_currentInstIcon)
+	{
+		ui->actionChangeInstIcon->setIcon(MMC->icons()->getIcon(m_currentInstIcon));
 	}
 }
 
+void MainWindow::updateInstanceToolIcon(QString new_icon)
+{
+	m_currentInstIcon = new_icon;
+	ui->actionChangeInstIcon->setIcon(MMC->icons()->getIcon(m_currentInstIcon));
+}
+
 void MainWindow::on_actionChangeInstGroup_triggered()
 {
 	if (!m_selectedInstance)
@@ -1095,7 +1115,6 @@ void MainWindow::instanceChanged(const QModelIndex &current, const QModelIndex &
 							.value<void *>()))
 	{
 		ui->instanceToolBar->setEnabled(true);
-		QString iconKey = m_selectedInstance->iconKey();
 		renameButton->setText(m_selectedInstance->name());
 		ui->actionChangeInstLWJGLVersion->setEnabled(
 			m_selectedInstance->menuActionEnabled("actionChangeInstLWJGLVersion"));
@@ -1104,8 +1123,7 @@ void MainWindow::instanceChanged(const QModelIndex &current, const QModelIndex &
 		ui->actionChangeInstMCVersion->setEnabled(
 			m_selectedInstance->menuActionEnabled("actionChangeInstMCVersion"));
 		m_statusLeft->setText(m_selectedInstance->getStatusbarDescription());
-		auto ico = MMC->icons()->getIcon(iconKey);
-		ui->actionChangeInstIcon->setIcon(ico);
+		updateInstanceToolIcon(m_selectedInstance->iconKey());
 
 		MMC->settings()->set("SelectedInstance", m_selectedInstance->id());
 	}
@@ -1120,12 +1138,11 @@ void MainWindow::instanceChanged(const QModelIndex &current, const QModelIndex &
 void MainWindow::selectionBad()
 {
 	m_selectedInstance = nullptr;
-	QString iconKey = "infinity";
+
 	statusBar()->clearMessage();
 	ui->instanceToolBar->setEnabled(false);
 	renameButton->setText(tr("Rename Instance"));
-	auto ico = MMC->icons()->getIcon(iconKey);
-	ui->actionChangeInstIcon->setIcon(ico);
+	updateInstanceToolIcon("infinity");
 }
 
 void MainWindow::on_actionEditInstNotes_triggered()
diff --git a/gui/MainWindow.h b/gui/MainWindow.h
index befe93e6..007c2e34 100644
--- a/gui/MainWindow.h
+++ b/gui/MainWindow.h
@@ -145,6 +145,9 @@ slots:
 	void assetsFailed();
 	void assetsFinished();
 
+	// called when an icon is changed in the icon model.
+	void iconUpdated(QString);
+
 public
 slots:
 	void instanceActivated(QModelIndex);
@@ -171,6 +174,7 @@ slots:
 protected:
 	bool eventFilter(QObject *obj, QEvent *ev);
 	void setCatBackground(bool enabled);
+	void updateInstanceToolIcon(QString new_icon);
 
 private:
 	Ui::MainWindow *ui;
@@ -180,9 +184,9 @@ private:
 	MinecraftProcess *proc;
 	ConsoleWindow *console;
 	LabeledToolButton *renameButton;
-	QToolButton *changeIconButton;
 
 	BaseInstance *m_selectedInstance;
+	QString m_currentInstIcon;
 
 	Task *m_versionLoadTask;
 
diff --git a/gui/dialogs/CopyInstanceDialog.cpp b/gui/dialogs/CopyInstanceDialog.cpp
index 9d7ac30c..4095408b 100644
--- a/gui/dialogs/CopyInstanceDialog.cpp
+++ b/gui/dialogs/CopyInstanceDialog.cpp
@@ -27,7 +27,7 @@
 
 #include "logic/InstanceFactory.h"
 #include "logic/BaseVersion.h"
-#include "logic/lists/IconList.h"
+#include "logic/icons/IconList.h"
 #include "logic/lists/MinecraftVersionList.h"
 #include "logic/tasks/Task.h"
 #include "logic/BaseInstance.h"
diff --git a/gui/dialogs/IconPickerDialog.cpp b/gui/dialogs/IconPickerDialog.cpp
index 99d6dc9a..cb832d95 100644
--- a/gui/dialogs/IconPickerDialog.cpp
+++ b/gui/dialogs/IconPickerDialog.cpp
@@ -25,7 +25,7 @@
 #include "gui/Platform.h"
 #include "gui/widgets/InstanceDelegate.h"
 
-#include "logic/lists/IconList.h"
+#include "logic/icons/IconList.h"
 
 IconPickerDialog::IconPickerDialog(QWidget *parent)
 	: QDialog(parent), ui(new Ui::IconPickerDialog)
diff --git a/gui/dialogs/NewInstanceDialog.cpp b/gui/dialogs/NewInstanceDialog.cpp
index 5b2cd086..c7b273af 100644
--- a/gui/dialogs/NewInstanceDialog.cpp
+++ b/gui/dialogs/NewInstanceDialog.cpp
@@ -19,7 +19,7 @@
 
 #include "logic/InstanceFactory.h"
 #include "logic/BaseVersion.h"
-#include "logic/lists/IconList.h"
+#include "logic/icons/IconList.h"
 #include "logic/lists/MinecraftVersionList.h"
 #include "logic/tasks/Task.h"
 
diff --git a/gui/dialogs/SettingsDialog.cpp b/gui/dialogs/SettingsDialog.cpp
index 30a973da..569c8f63 100644
--- a/gui/dialogs/SettingsDialog.cpp
+++ b/gui/dialogs/SettingsDialog.cpp
@@ -102,6 +102,18 @@ void SettingsDialog::on_instDirBrowseBtn_clicked()
 		ui->instDirTextBox->setText(cooked_dir);
 	}
 }
+void SettingsDialog::on_iconsDirBrowseBtn_clicked()
+{
+	QString raw_dir = QFileDialog::getExistingDirectory(this, tr("Icons Directory"),
+														ui->iconsDirTextBox->text());
+	QString cooked_dir = NormalizePath(raw_dir);
+
+	// do not allow current dir - it's dirty. Do not allow dirs that don't exist
+	if (!cooked_dir.isEmpty() && QDir(cooked_dir).exists())
+	{
+		ui->iconsDirTextBox->setText(cooked_dir);
+	}
+}
 
 void SettingsDialog::on_modsDirBrowseBtn_clicked()
 {
@@ -205,6 +217,7 @@ void SettingsDialog::applySettings(SettingsObject *s)
 	s->set("InstanceDir", ui->instDirTextBox->text());
 	s->set("CentralModsDir", ui->modsDirTextBox->text());
 	s->set("LWJGLDir", ui->lwjglDirTextBox->text());
+	s->set("IconsDir", ui->iconsDirTextBox->text());
 
 	// Editors
 	QString jsonEditor = ui->jsonEditorTextBox->text();
@@ -271,6 +284,7 @@ void SettingsDialog::loadSettings(SettingsObject *s)
 	ui->instDirTextBox->setText(s->get("InstanceDir").toString());
 	ui->modsDirTextBox->setText(s->get("CentralModsDir").toString());
 	ui->lwjglDirTextBox->setText(s->get("LWJGLDir").toString());
+	ui->iconsDirTextBox->setText(s->get("IconsDir").toString());
 
 	// Editors
 	ui->jsonEditorTextBox->setText(s->get("JsonEditor").toString());
diff --git a/gui/dialogs/SettingsDialog.h b/gui/dialogs/SettingsDialog.h
index 01357c91..bcf57a80 100644
--- a/gui/dialogs/SettingsDialog.h
+++ b/gui/dialogs/SettingsDialog.h
@@ -55,8 +55,11 @@ slots:
 
 	void on_lwjglDirBrowseBtn_clicked();
 
+
 	void on_jsonEditorBrowseBtn_clicked();
 
+	void on_iconsDirBrowseBtn_clicked();
+
 	void on_maximizedCheckBox_clicked(bool checked);
 
 	void on_buttonBox_accepted();
diff --git a/gui/dialogs/SettingsDialog.ui b/gui/dialogs/SettingsDialog.ui
index ec4d156e..dbc8ca88 100644
--- a/gui/dialogs/SettingsDialog.ui
+++ b/gui/dialogs/SettingsDialog.ui
@@ -215,6 +215,9 @@
           <item row="1" column="1">
            <widget class="QLineEdit" name="modsDirTextBox"/>
           </item>
+          <item row="2" column="1">
+           <widget class="QLineEdit" name="lwjglDirTextBox"/>
+          </item>
           <item row="1" column="2">
            <widget class="QToolButton" name="modsDirBrowseBtn">
             <property name="text">
@@ -229,9 +232,6 @@
             </property>
            </widget>
           </item>
-          <item row="2" column="1">
-           <widget class="QLineEdit" name="lwjglDirTextBox"/>
-          </item>
           <item row="2" column="2">
            <widget class="QToolButton" name="lwjglDirBrowseBtn">
             <property name="text">
@@ -239,6 +239,23 @@
             </property>
            </widget>
           </item>
+          <item row="3" column="1">
+           <widget class="QLineEdit" name="iconsDirTextBox"/>
+          </item>
+          <item row="3" column="0">
+           <widget class="QLabel" name="labelIconsDir">
+            <property name="text">
+             <string>Icons:</string>
+            </property>
+           </widget>
+          </item>
+          <item row="3" column="2">
+           <widget class="QToolButton" name="iconsDirBrowseBtn">
+            <property name="text">
+             <string>...</string>
+            </property>
+           </widget>
+          </item>
          </layout>
         </widget>
        </item>
diff --git a/logic/BaseInstance.cpp b/logic/BaseInstance.cpp
index bc82fee1..b39db03b 100644
--- a/logic/BaseInstance.cpp
+++ b/logic/BaseInstance.cpp
@@ -27,6 +27,7 @@
 
 #include "pathutils.h"
 #include "lists/MinecraftVersionList.h"
+#include "logic/icons/IconList.h"
 
 BaseInstance::BaseInstance(BaseInstancePrivate *d_in, const QString &rootDir,
 						   SettingsObject *settings_obj, QObject *parent)
@@ -38,6 +39,7 @@ BaseInstance::BaseInstance(BaseInstancePrivate *d_in, const QString &rootDir,
 
 	settings().registerSetting(new Setting("name", "Unnamed Instance"));
 	settings().registerSetting(new Setting("iconKey", "default"));
+	connect(MMC->icons().get(), SIGNAL(iconUpdated(QString)), SLOT(iconUpdated(QString)));
 	settings().registerSetting(new Setting("notes", ""));
 	settings().registerSetting(new Setting("lastLaunchTime", 0));
 
@@ -93,6 +95,14 @@ BaseInstance::BaseInstance(BaseInstancePrivate *d_in, const QString &rootDir,
 		"AutoCloseConsole", globalSettings->getSetting("AutoCloseConsole")));
 }
 
+void BaseInstance::iconUpdated(QString key)
+{
+	if(iconKey() == key)
+	{
+		emit propertiesChanged(this);
+	}
+}
+
 void BaseInstance::nuke()
 {
 	QDir(instanceRoot()).removeRecursively();
diff --git a/logic/BaseInstance.h b/logic/BaseInstance.h
index 5f426676..01d6dc7d 100644
--- a/logic/BaseInstance.h
+++ b/logic/BaseInstance.h
@@ -184,6 +184,9 @@ signals:
 	 */
 	void nuked(BaseInstance *inst);
 
+protected slots:
+	void iconUpdated(QString key);
+
 protected:
 	std::shared_ptr<BaseInstancePrivate> inst_d;
 };
diff --git a/logic/LegacyInstance.cpp b/logic/LegacyInstance.cpp
index 5c82b837..08d7c147 100644
--- a/logic/LegacyInstance.cpp
+++ b/logic/LegacyInstance.cpp
@@ -27,7 +27,7 @@
 
 #include "logic/MinecraftProcess.h"
 #include "logic/LegacyUpdate.h"
-#include "logic/lists/IconList.h"
+#include "logic/icons/IconList.h"
 
 #include "gui/dialogs/LegacyModEditDialog.h"
 
diff --git a/logic/icons/IconList.cpp b/logic/icons/IconList.cpp
new file mode 100644
index 00000000..1e692d1d
--- /dev/null
+++ b/logic/icons/IconList.cpp
@@ -0,0 +1,351 @@
+/* Copyright 2013 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "IconList.h"
+#include <pathutils.h>
+#include <settingsobject.h>
+#include <QMap>
+#include <QEventLoop>
+#include <QMimeData>
+#include <QUrl>
+#include <QFileSystemWatcher>
+#include <MultiMC.h>
+#include <setting.h>
+
+#define MAX_SIZE 1024
+
+IconList::IconList(QObject *parent) : QAbstractListModel(parent)
+{
+	// add builtin icons
+	QDir instance_icons(":/icons/instances/");
+	auto file_info_list = instance_icons.entryInfoList(QDir::Files, QDir::Name);
+	for (auto file_info : file_info_list)
+	{
+		QString key = file_info.baseName();
+		addIcon(key, key, file_info.absoluteFilePath(), MMCIcon::Builtin);
+	}
+
+	m_watcher.reset(new QFileSystemWatcher());
+	is_watching = false;
+	connect(m_watcher.get(), SIGNAL(directoryChanged(QString)),
+			SLOT(directoryChanged(QString)));
+	connect(m_watcher.get(), SIGNAL(fileChanged(QString)), SLOT(fileChanged(QString)));
+	
+	auto setting = MMC->settings()->getSetting("IconsDir");
+	QString path = setting->get().toString();
+	connect(setting, SIGNAL(settingChanged(const Setting &, QVariant)),
+			SLOT(settingChanged(const Setting &, QVariant)));
+	directoryChanged(path);
+}
+
+void IconList::directoryChanged(const QString &path)
+{
+	QDir new_dir (path);
+	if(m_dir.absolutePath() != new_dir.absolutePath())
+	{
+		m_dir.setPath(path);
+		m_dir.refresh();
+		if(is_watching)
+			stopWatching();
+		startWatching();
+	}
+	if(!m_dir.exists())
+		if(!ensureFolderPathExists(m_dir.absolutePath()))
+			return;
+	m_dir.refresh();
+	auto new_list = m_dir.entryList(QDir::Files, QDir::Name);
+	for (auto it = new_list.begin(); it != new_list.end(); it++)
+	{
+		QString &foo = (*it);
+		foo = m_dir.filePath(foo);
+	}
+	auto new_set = new_list.toSet();
+	QList<QString> current_list;
+	for (auto &it : icons)
+	{
+		if (!it.has(MMCIcon::FileBased))
+			continue;
+		current_list.push_back(it.m_images[MMCIcon::FileBased].filename);
+	}
+	QSet<QString> current_set = current_list.toSet();
+
+	QSet<QString> to_remove = current_set;
+	to_remove -= new_set;
+
+	QSet<QString> to_add = new_set;
+	to_add -= current_set;
+
+	for (auto remove : to_remove)
+	{
+		QLOG_INFO() << "Removing " << remove;
+		QFileInfo rmfile(remove);
+		QString key = rmfile.baseName();
+		int idx = getIconIndex(key);
+		if (idx == -1)
+			continue;
+		icons[idx].remove(MMCIcon::FileBased);
+		if (icons[idx].type() == MMCIcon::ToBeDeleted)
+		{
+			beginRemoveRows(QModelIndex(), idx, idx);
+			icons.remove(idx);
+			reindex();
+			endRemoveRows();
+		}
+		else
+		{
+			dataChanged(index(idx), index(idx));
+		}
+		m_watcher->removePath(remove);
+		emit iconUpdated(key);
+	}
+
+	for (auto add : to_add)
+	{
+		QLOG_INFO() << "Adding " << add;
+		QFileInfo addfile(add);
+		QString key = addfile.baseName();
+		if (addIcon(key, QString(), addfile.filePath(), MMCIcon::FileBased))
+		{
+			m_watcher->addPath(add);
+			emit iconUpdated(key);
+		}
+	}
+}
+
+void IconList::fileChanged(const QString &path)
+{
+	QLOG_INFO() << "Checking " << path;
+	QFileInfo checkfile(path);
+	if (!checkfile.exists())
+		return;
+	QString key = checkfile.baseName();
+	int idx = getIconIndex(key);
+	if (idx == -1)
+		return;
+	QIcon icon(path);
+	if (!icon.availableSizes().size())
+		return;
+
+	icons[idx].m_images[MMCIcon::FileBased].icon = icon;
+	dataChanged(index(idx), index(idx));
+	emit iconUpdated(key);
+}
+
+void IconList::settingChanged(const Setting &setting, QVariant value)
+{
+	if(setting.configKey() != "IconsDir")
+		return;
+
+	directoryChanged(value.toString());
+}
+
+void IconList::startWatching()
+{
+	auto abs_path = m_dir.absolutePath();
+	ensureFolderPathExists(abs_path);
+	is_watching = m_watcher->addPath(abs_path);
+	if (is_watching)
+	{
+		QLOG_INFO() << "Started watching " << abs_path;
+	}
+	else
+	{
+		QLOG_INFO() << "Failed to start watching " << abs_path;
+	}
+}
+
+void IconList::stopWatching()
+{
+	m_watcher->removePaths(m_watcher->files());
+	m_watcher->removePaths(m_watcher->directories());
+	is_watching = false;
+}
+
+QStringList IconList::mimeTypes() const
+{
+	QStringList types;
+	types << "text/uri-list";
+	return types;
+}
+Qt::DropActions IconList::supportedDropActions() const
+{
+	return Qt::CopyAction;
+}
+
+bool IconList::dropMimeData(const QMimeData *data, Qt::DropAction action, int row, int column,
+							const QModelIndex &parent)
+{
+	if (action == Qt::IgnoreAction)
+		return true;
+	// check if the action is supported
+	if (!data || !(action & supportedDropActions()))
+		return false;
+
+	// files dropped from outside?
+	if (data->hasUrls())
+	{
+		auto urls = data->urls();
+		QStringList iconFiles;
+		for (auto url : urls)
+		{
+			// only local files may be dropped...
+			if (!url.isLocalFile())
+				continue;
+			iconFiles += url.toLocalFile();
+		}
+		installIcons(iconFiles);
+		return true;
+	}
+	return false;
+}
+
+Qt::ItemFlags IconList::flags(const QModelIndex &index) const
+{
+	Qt::ItemFlags defaultFlags = QAbstractListModel::flags(index);
+	if (index.isValid())
+		return Qt::ItemIsDropEnabled | defaultFlags;
+	else
+		return Qt::ItemIsDropEnabled | defaultFlags;
+}
+
+QVariant IconList::data(const QModelIndex &index, int role) const
+{
+	if (!index.isValid())
+		return QVariant();
+
+	int row = index.row();
+
+	if (row < 0 || row >= icons.size())
+		return QVariant();
+
+	switch (role)
+	{
+	case Qt::DecorationRole:
+		return icons[row].icon();
+	case Qt::DisplayRole:
+		return icons[row].name();
+	case Qt::UserRole:
+		return icons[row].m_key;
+	default:
+		return QVariant();
+	}
+}
+
+int IconList::rowCount(const QModelIndex &parent) const
+{
+	return icons.size();
+}
+
+void IconList::installIcons(QStringList iconFiles)
+{
+	for (QString file : iconFiles)
+	{
+		QFileInfo fileinfo(file);
+		if (!fileinfo.isReadable() || !fileinfo.isFile())
+			continue;
+		QString target = PathCombine("icons", fileinfo.fileName());
+
+		QString suffix = fileinfo.suffix();
+		if (suffix != "jpeg" && suffix != "png" && suffix != "jpg")
+			continue;
+
+		if (!QFile::copy(file, target))
+			continue;
+	}
+}
+
+bool IconList::deleteIcon(QString key)
+{
+	int iconIdx = getIconIndex(key);
+	if (iconIdx == -1)
+		return false;
+	auto &iconEntry = icons[iconIdx];
+	if (iconEntry.has(MMCIcon::FileBased))
+	{
+		return QFile::remove(iconEntry.m_images[MMCIcon::FileBased].filename);
+	}
+	return false;
+}
+
+bool IconList::addIcon(QString key, QString name, QString path, MMCIcon::Type type)
+{
+	// replace the icon even? is the input valid?
+	QIcon icon(path);
+	if (!icon.availableSizes().size())
+		return false;
+	auto iter = name_index.find(key);
+	if (iter != name_index.end())
+	{
+		auto &oldOne = icons[*iter];
+		oldOne.replace(type, icon, path);
+		dataChanged(index(*iter), index(*iter));
+		return true;
+	}
+	else
+	{
+		// add a new icon
+		beginInsertRows(QModelIndex(), icons.size(), icons.size());
+		{
+			MMCIcon mmc_icon;
+			mmc_icon.m_name = name;
+			mmc_icon.m_key = key;
+			mmc_icon.replace(type, icon, path);
+			icons.push_back(mmc_icon);
+			name_index[key] = icons.size() - 1;
+		}
+		endInsertRows();
+		return true;
+	}
+}
+
+void IconList::reindex()
+{
+	name_index.clear();
+	int i = 0;
+	for (auto &iter : icons)
+	{
+		name_index[iter.m_key] = i;
+		i++;
+	}
+}
+
+QIcon IconList::getIcon(QString key)
+{
+	int icon_index = getIconIndex(key);
+
+	if (icon_index != -1)
+		return icons[icon_index].icon();
+
+	// Fallback for icons that don't exist.
+	icon_index = getIconIndex("infinity");
+
+	if (icon_index != -1)
+		return icons[icon_index].icon();
+	return QIcon();
+}
+
+int IconList::getIconIndex(QString key)
+{
+	if (key == "default")
+		key = "infinity";
+
+	auto iter = name_index.find(key);
+	if (iter != name_index.end())
+		return *iter;
+
+	return -1;
+}
+
+//#include "IconList.moc"
\ No newline at end of file
diff --git a/logic/lists/IconList.h b/logic/icons/IconList.h
index 40ad043b..322411d1 100644
--- a/logic/lists/IconList.h
+++ b/logic/icons/IconList.h
@@ -17,15 +17,21 @@
 
 #include <QMutex>
 #include <QAbstractListModel>
+#include <QFile>
+#include <QDir>
 #include <QtGui/QIcon>
+#include <memory>
+#include "MMCIcon.h"
+#include "setting.h"
 
-class Private;
+class QFileSystemWatcher;
 
 class IconList : public QAbstractListModel
 {
+	Q_OBJECT
 public:
-	IconList();
-	virtual ~IconList();
+	explicit IconList(QObject *parent = 0);
+	virtual ~IconList() {};
 
 	QIcon getIcon(QString key);
 	int getIconIndex(QString key);
@@ -33,7 +39,7 @@ public:
 	virtual QVariant data(const QModelIndex &index, int role = Qt::DisplayRole) const;
 	virtual int rowCount(const QModelIndex &parent = QModelIndex()) const;
 
-	bool addIcon(QString key, QString name, QString path, bool is_builtin = false);
+	bool addIcon(QString key, QString name, QString path, MMCIcon::Type type);
 	bool deleteIcon(QString key);
 
 	virtual QStringList mimeTypes() const;
@@ -44,11 +50,28 @@ public:
 
 	void installIcons(QStringList iconFiles);
 
+	void startWatching();
+	void stopWatching();
+
+signals:
+	void iconUpdated(QString key);
+
 private:
 	// hide copy constructor
 	IconList(const IconList &) = delete;
 	// hide assign op
 	IconList &operator=(const IconList &) = delete;
 	void reindex();
-	Private *d;
+
+protected
+slots:
+	void directoryChanged(const QString &path);
+	void fileChanged(const QString &path);
+	void settingChanged(const Setting & setting, QVariant value);
+private:
+	std::shared_ptr<QFileSystemWatcher> m_watcher;
+	bool is_watching;
+	QMap<QString, int> name_index;
+	QVector<MMCIcon> icons;
+	QDir m_dir;
 };
diff --git a/logic/icons/MMCIcon.cpp b/logic/icons/MMCIcon.cpp
new file mode 100644
index 00000000..d721513d
--- /dev/null
+++ b/logic/icons/MMCIcon.cpp
@@ -0,0 +1,89 @@
+/* Copyright 2013 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "MMCIcon.h"
+#include <QFileInfo>
+
+MMCIcon::Type operator--(MMCIcon::Type &t, int)
+{
+	MMCIcon::Type temp = t;
+	switch (t)
+	{
+	case MMCIcon::Type::Builtin:
+		t = MMCIcon::Type::ToBeDeleted;
+		break;
+	case MMCIcon::Type::Transient:
+		t = MMCIcon::Type::Builtin;
+		break;
+	case MMCIcon::Type::FileBased:
+		t = MMCIcon::Type::Transient;
+		break;
+	default:
+	{
+	}
+	}
+	return temp;
+}
+
+MMCIcon::Type MMCIcon::type() const
+{
+	return m_current_type;
+}
+
+QString MMCIcon::name() const
+{
+	if (m_name.size())
+		return m_name;
+	return m_key;
+}
+
+bool MMCIcon::has(MMCIcon::Type _type) const
+{
+	return m_images[_type].present();
+}
+
+QIcon MMCIcon::icon() const
+{
+	if (m_current_type == Type::ToBeDeleted)
+		return QIcon();
+	return m_images[m_current_type].icon;
+}
+
+void MMCIcon::remove(Type rm_type)
+{
+	m_images[rm_type].filename = QString();
+	m_images[rm_type].icon = QIcon();
+	for (auto iter = rm_type; iter != Type::ToBeDeleted; iter--)
+	{
+		if (m_images[iter].present())
+		{
+			m_current_type = iter;
+			return;
+		}
+	}
+	m_current_type = Type::ToBeDeleted;
+}
+
+void MMCIcon::replace(MMCIcon::Type new_type, QIcon icon, QString path)
+{
+	QFileInfo foo(path);
+	if (new_type > m_current_type || m_current_type == MMCIcon::ToBeDeleted)
+	{
+		m_current_type = new_type;
+	}
+	m_images[new_type].icon = icon;
+	m_images[new_type].changed = foo.lastModified();
+	m_images[new_type].filename = path;
+}
diff --git a/logic/icons/MMCIcon.h b/logic/icons/MMCIcon.h
new file mode 100644
index 00000000..5e4b3bb6
--- /dev/null
+++ b/logic/icons/MMCIcon.h
@@ -0,0 +1,52 @@
+/* Copyright 2013 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+#include <QString>
+#include <QDateTime>
+#include <QIcon>
+struct MMCImage
+{
+	QIcon icon;
+	QString filename;
+	QDateTime changed;
+	bool present() const
+	{
+		return !icon.isNull();
+	}
+};
+
+struct MMCIcon
+{
+	enum Type : unsigned
+	{
+		Builtin,
+		Transient,
+		FileBased,
+		ICONS_TOTAL,
+		ToBeDeleted
+	};
+	QString m_key;
+	QString m_name;
+	MMCImage m_images[ICONS_TOTAL];
+	Type m_current_type = ToBeDeleted;
+
+	Type type() const;
+	QString name() const;
+	bool has(Type _type) const;
+	QIcon icon() const;
+	void remove(Type rm_type);
+	void replace(Type new_type, QIcon icon, QString path = QString());
+};
diff --git a/logic/lists/IconList.cpp b/logic/lists/IconList.cpp
deleted file mode 100644
index ecfb8c3c..00000000
--- a/logic/lists/IconList.cpp
+++ /dev/null
@@ -1,271 +0,0 @@
-/* Copyright 2013 MultiMC Contributors
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#include "IconList.h"
-#include <pathutils.h>
-#include <QMap>
-#include <QEventLoop>
-#include <QDir>
-#include <QMimeData>
-#include <QUrl>
-#define MAX_SIZE 1024
-
-struct entry
-{
-	QString key;
-	QString name;
-	QIcon icon;
-	bool is_builtin;
-	QString filename;
-};
-
-class Private : public QObject
-{
-	Q_OBJECT
-public:
-	QMap<QString, int> index;
-	QVector<entry> icons;
-	Private()
-	{
-	}
-};
-
-IconList::IconList() : QAbstractListModel(), d(new Private())
-{
-	QDir instance_icons(":/icons/instances/");
-	auto file_info_list = instance_icons.entryInfoList(QDir::Files, QDir::Name);
-	for (auto file_info : file_info_list)
-	{
-		QString key = file_info.baseName();
-		addIcon(key, key, file_info.absoluteFilePath(), true);
-	}
-
-	// FIXME: get from settings
-	ensureFolderPathExists("icons");
-	QDir user_icons("icons");
-	file_info_list = user_icons.entryInfoList(QDir::Files, QDir::Name);
-	for (auto file_info : file_info_list)
-	{
-		QString filename = file_info.absoluteFilePath();
-		QString key = file_info.baseName();
-		addIcon(key, key, filename);
-	}
-}
-
-IconList::~IconList()
-{
-	delete d;
-	d = nullptr;
-}
-
-QStringList IconList::mimeTypes() const
-{
-	QStringList types;
-	types << "text/uri-list";
-	return types;
-}
-Qt::DropActions IconList::supportedDropActions() const
-{
-	return Qt::CopyAction;
-}
-
-bool IconList::dropMimeData(const QMimeData *data, Qt::DropAction action, int row, int column,
-							const QModelIndex &parent)
-{
-	if (action == Qt::IgnoreAction)
-		return true;
-	// check if the action is supported
-	if (!data || !(action & supportedDropActions()))
-		return false;
-
-	// files dropped from outside?
-	if (data->hasUrls())
-	{
-		/*
-		bool was_watching = is_watching;
-		if(was_watching)
-			stopWatching();
-		*/
-		auto urls = data->urls();
-		QStringList iconFiles;
-		for (auto url : urls)
-		{
-			// only local files may be dropped...
-			if (!url.isLocalFile())
-				continue;
-			iconFiles += url.toLocalFile();
-		}
-		installIcons(iconFiles);
-		/*
-		if(was_watching)
-			startWatching();
-		*/
-		return true;
-	}
-	return false;
-}
-
-Qt::ItemFlags IconList::flags(const QModelIndex &index) const
-{
-	Qt::ItemFlags defaultFlags = QAbstractListModel::flags(index);
-	if (index.isValid())
-		return Qt::ItemIsDropEnabled | defaultFlags;
-	else
-		return Qt::ItemIsDropEnabled | defaultFlags;
-}
-
-QVariant IconList::data(const QModelIndex &index, int role) const
-{
-	if (!index.isValid())
-		return QVariant();
-
-	int row = index.row();
-
-	if (row < 0 || row >= d->icons.size())
-		return QVariant();
-
-	switch (role)
-	{
-	case Qt::DecorationRole:
-		return d->icons[row].icon;
-	case Qt::DisplayRole:
-		return d->icons[row].name;
-	case Qt::UserRole:
-		return d->icons[row].key;
-	default:
-		return QVariant();
-	}
-}
-
-int IconList::rowCount(const QModelIndex &parent) const
-{
-	return d->icons.size();
-}
-
-void IconList::installIcons(QStringList iconFiles)
-{
-	for (QString file : iconFiles)
-	{
-		QFileInfo fileinfo(file);
-		if (!fileinfo.isReadable() || !fileinfo.isFile())
-			continue;
-		QString target = PathCombine("icons", fileinfo.fileName());
-
-		QString suffix = fileinfo.suffix();
-		if (suffix != "jpeg" && suffix != "png" && suffix != "jpg")
-			continue;
-
-		if (!QFile::copy(file, target))
-			continue;
-
-		QString key = fileinfo.baseName();
-		addIcon(key, key, target);
-	}
-}
-
-bool IconList::deleteIcon(QString key)
-{
-	int iconIdx = getIconIndex(key);
-	if (iconIdx == -1)
-		return false;
-	auto &iconEntry = d->icons[iconIdx];
-	if (iconEntry.is_builtin)
-		return false;
-	if (QFile::remove(iconEntry.filename))
-	{
-		beginRemoveRows(QModelIndex(), iconIdx, iconIdx);
-		d->icons.remove(iconIdx);
-		reindex();
-		endRemoveRows();
-	}
-	return true;
-}
-
-bool IconList::addIcon(QString key, QString name, QString path, bool is_builtin)
-{
-	auto iter = d->index.find(key);
-	if (iter != d->index.end())
-	{
-		if (d->icons[*iter].is_builtin)
-			return false;
-
-		QIcon icon(path);
-		if (icon.isNull())
-			return false;
-
-		auto &oldOne = d->icons[*iter];
-
-		if (!QFile::remove(oldOne.filename))
-			return false;
-
-		// replace the icon
-		oldOne = {key, name, icon, is_builtin, path};
-		dataChanged(index(*iter), index(*iter));
-		return true;
-	}
-	else
-	{
-		QIcon icon(path);
-		if (icon.isNull())
-			return false;
-
-		// add a new icon
-		beginInsertRows(QModelIndex(), d->icons.size(), d->icons.size());
-		d->icons.push_back({key, name, icon, is_builtin, path});
-		d->index[key] = d->icons.size() - 1;
-		endInsertRows();
-		return true;
-	}
-}
-
-void IconList::reindex()
-{
-	d->index.clear();
-	int i = 0;
-	for (auto &iter : d->icons)
-	{
-		d->index[iter.key] = i;
-		i++;
-	}
-}
-
-QIcon IconList::getIcon(QString key)
-{
-	int icon_index = getIconIndex(key);
-
-	if (icon_index != -1)
-		return d->icons[icon_index].icon;
-
-	// Fallback for icons that don't exist.
-	icon_index = getIconIndex("infinity");
-
-	if (icon_index != -1)
-		return d->icons[icon_index].icon;
-	return QIcon();
-}
-
-int IconList::getIconIndex(QString key)
-{
-	if (key == "default")
-		key = "infinity";
-
-	auto iter = d->index.find(key);
-	if (iter != d->index.end())
-		return *iter;
-
-	return -1;
-}
-
-#include "IconList.moc"
\ No newline at end of file
diff --git a/logic/lists/InstanceList.cpp b/logic/lists/InstanceList.cpp
index 0ecb387d..48a2865a 100644
--- a/logic/lists/InstanceList.cpp
+++ b/logic/lists/InstanceList.cpp
@@ -28,7 +28,7 @@
 
 #include "MultiMC.h"
 #include "logic/lists/InstanceList.h"
-#include "logic/lists/IconList.h"
+#include "logic/icons/IconList.h"
 #include "logic/lists/MinecraftVersionList.h"
 #include "logic/BaseInstance.h"
 #include "logic/InstanceFactory.h"
@@ -356,12 +356,13 @@ void InstanceList::loadForgeInstances(QMap<QString, QString> groupMap)
 
 		QString iconKey = record.logo;
 		iconKey.remove(QRegularExpression("\\..*"));
-		MMC->icons()->addIcon(iconKey, iconKey, PathCombine(templateDir, record.logo), true);
+		MMC->icons()->addIcon(iconKey, iconKey, PathCombine(templateDir, record.logo),
+							  MMCIcon::Transient);
 
 		if (!QFileInfo(PathCombine(instanceDir, "instance.cfg")).exists())
 		{
 			BaseInstance *instPtr = NULL;
-			auto & factory = InstanceFactory::get();
+			auto &factory = InstanceFactory::get();
 			auto version = MMC->minecraftlist()->findVersion(record.mcVersion);
 			if (!version)
 			{