implemented "value hints" for choosing output values to use

app/widget/CMakeLists.txt

@@ -33,6 +33,7 @@ add_subdirectory(nodecombobox)
 add_subdirectory(nodeparamview)
 add_subdirectory(nodetableview)
 add_subdirectory(nodetreeview)
+add_subdirectory(nodevaluetree)
 add_subdirectory(nodeview)
 add_subdirectory(panel)
 add_subdirectory(path)

app/widget/nodeparamview/nodeparamviewconnectedlabel.cpp

@@ -25,6 +25,7 @@
 #include "common/qtutils.h"
 #include "core.h"
 #include "node/node.h"
+#include "widget/collapsebutton/collapsebutton.h"
 #include "widget/menu/menu.h"
 #include "widget/nodeview/nodeviewundo.h"
 
@@ -35,20 +36,29 @@ NodeParamViewConnectedLabel::NodeParamViewConnectedLabel(const NodeInput &input,
   input_(input),
   connected_node_(nullptr)
 {
-  QHBoxLayout* layout = new QHBoxLayout(this);
-  layout->setSpacing(QtUtils::QFontMetricsWidth(fontMetrics(), QStringLiteral(" ")));
+  QVBoxLayout *layout = new QVBoxLayout(this);
   layout->setMargin(0);
 
-  layout->addWidget(new QLabel(tr("Connected to")));
+  // Set up label area
+  QHBoxLayout *label_layout = new QHBoxLayout();
+  label_layout->setSpacing(QtUtils::QFontMetricsWidth(fontMetrics(), QStringLiteral(" ")));
+  label_layout->setMargin(0);
+  layout->addLayout(label_layout);
+
+  CollapseButton *collapse_btn = new CollapseButton();
+  collapse_btn->setChecked(false);
+  label_layout->addWidget(collapse_btn);
+
+  label_layout->addWidget(new QLabel(tr("Connected to")));
 
   connected_to_lbl_ = new ClickableLabel();
   connected_to_lbl_->setCursor(Qt::PointingHandCursor);
   connected_to_lbl_->setContextMenuPolicy(Qt::CustomContextMenu);
   connect(connected_to_lbl_, &ClickableLabel::MouseClicked, this, &NodeParamViewConnectedLabel::ConnectionClicked);
   connect(connected_to_lbl_, &ClickableLabel::customContextMenuRequested, this, &NodeParamViewConnectedLabel::ShowLabelContextMenu);
-  layout->addWidget(connected_to_lbl_);
+  label_layout->addWidget(connected_to_lbl_);
 
-  layout->addStretch();
+  label_layout->addStretch();
 
   // Set up "link" font
   QFont link_font = connected_to_lbl_->font();
@@ -64,6 +74,21 @@ NodeParamViewConnectedLabel::NodeParamViewConnectedLabel(const NodeInput &input,
 
   connect(input_.node(), &Node::InputConnected, this, &NodeParamViewConnectedLabel::InputConnected);
   connect(input_.node(), &Node::InputDisconnected, this, &NodeParamViewConnectedLabel::InputDisconnected);
+
+  // Set up table area
+  value_tree_ = new NodeValueTree();
+  value_tree_->setVisible(false);
+  layout->addWidget(value_tree_);
+  connect(collapse_btn, &CollapseButton::toggled, this, &NodeParamViewConnectedLabel::SetValueTreeVisible);
+}
+
+void NodeParamViewConnectedLabel::SetTime(const rational &time)
+{
+  time_ = time;
+
+  if (value_tree_->isVisible()) {
+    UpdateValueTree();
+  }
 }
 
 void NodeParamViewConnectedLabel::InputConnected(Node *output, const NodeInput& input)
@@ -122,4 +147,18 @@ void NodeParamViewConnectedLabel::UpdateLabel()
   connected_to_lbl_->setText(s);
 }
 
+void NodeParamViewConnectedLabel::UpdateValueTree()
+{
+  value_tree_->SetNode(input_, time_);
+}
+
+void NodeParamViewConnectedLabel::SetValueTreeVisible(bool e)
+{
+  value_tree_->setVisible(e);
+
+  if (e) {
+    UpdateValueTree();
+  }
+}
+
 }

app/widget/nodeparamview/nodeparamviewconnectedlabel.h

@@ -23,6 +23,7 @@
 
 #include "node/param.h"
 #include "widget/clickablelabel/clickablelabel.h"
+#include "widget/nodevaluetree/nodevaluetree.h"
 
 namespace olive {
 
@@ -31,6 +32,8 @@ class NodeParamViewConnectedLabel : public QWidget {
 public:
   NodeParamViewConnectedLabel(const NodeInput& input, QWidget* parent = nullptr);
 
+  void SetTime(const rational &time);
+
 signals:
   void RequestSelectNode(const QVector<Node*>& node);
 
@@ -46,12 +49,21 @@ private slots:
 private:
   void UpdateLabel();
 
+  void UpdateValueTree();
+
   ClickableLabel* connected_to_lbl_;
 
   NodeInput input_;
 
   Node *connected_node_;
 
+  NodeValueTree *value_tree_;
+
+  rational time_;
+
+private slots:
+  void SetValueTreeVisible(bool e);
+
 };
 
 }

app/widget/nodeparamview/nodeparamviewitem.cpp

@@ -383,6 +383,10 @@ void NodeParamViewItemBody::SetTime(const rational &time)
       ui_obj.key_control->SetTime(time);
     }
 
+    if (ui_obj.connected_label) {
+      ui_obj.connected_label->SetTime(time);
+    }
+
     ui_obj.widget_bridge->SetTime(time);
   }
 }

app/widget/nodevaluetree/CMakeLists.txt

@@ -0,0 +1,22 @@
+# Olive - Non-Linear Video Editor
+# Copyright (C) 2021 Olive Team
+#
+# This program 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.
+#
+# This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+
+set(OLIVE_SOURCES
+  ${OLIVE_SOURCES}
+  widget/nodevaluetree/nodevaluetree.cpp
+  widget/nodevaluetree/nodevaluetree.h
+  PARENT_SCOPE
+)

app/widget/nodevaluetree/nodevaluetree.cpp

@@ -0,0 +1,83 @@
+#include "nodevaluetree.h"
+
+#include <QEvent>
+
+#include "node/traverser.h"
+
+namespace olive {
+
+#define super QTreeWidget
+
+NodeValueTree::NodeValueTree(QWidget *parent) :
+  super(parent)
+{
+  setColumnWidth(0, 0);
+  setColumnCount(4);
+  setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
+
+  static const int kMinimumRows = 10;
+  setMinimumHeight(fontMetrics().height() * kMinimumRows);
+
+  Retranslate();
+}
+
+void NodeValueTree::SetNode(const NodeInput &input, const rational &time)
+{
+  clear();
+
+  NodeTraverser traverser;
+
+  Node *connected_node = input.GetConnectedOutput();
+  Node::ValueHint value_hint = input.node()->GetValueHintForInput(input.input(), input.element());
+
+  NodeValueTable table = traverser.GenerateTable(connected_node, value_hint, TimeRange(time, time));
+
+  int index = traverser.GenerateRowValueElementIndex(input.node(), input.input(), input.element(), &table);
+
+  for (int i=0; i<table.Count(); i++) {
+    const NodeValue &value = table.at(i);
+    QTreeWidgetItem *item = new QTreeWidgetItem(this);
+
+    Node::ValueHint hint = {{value.type()}, table.Count()-1-i, value.tag()};
+
+    QRadioButton *radio = new QRadioButton(this);
+    radio->setProperty("input", QVariant::fromValue(input));
+    radio->setProperty("hint", QVariant::fromValue(hint));
+    if (i == index) {
+      radio->setChecked(true);
+    }
+    connect(radio, &QRadioButton::clicked, this, &NodeValueTree::RadioButtonChecked);
+
+    setItemWidget(item, 0, radio);
+    item->setText(1, NodeValue::GetPrettyDataTypeName(value.type()));
+    item->setText(2, NodeValue::ValueToString(value.type(), value.data(), false));
+    item->setText(3, value.source()->GetLabelAndName());
+  }
+}
+
+void NodeValueTree::changeEvent(QEvent *event)
+{
+  if (event->type() == QEvent::LanguageChange) {
+    Retranslate();
+  }
+
+  super::changeEvent(event);
+}
+
+void NodeValueTree::Retranslate()
+{
+  setHeaderLabels({QString(), tr("Type"), tr("Value"), tr("Source")});
+}
+
+void NodeValueTree::RadioButtonChecked(bool e)
+{
+  if (e) {
+    QRadioButton *btn = static_cast<QRadioButton*>(sender());
+    Node::ValueHint hint = btn->property("hint").value<Node::ValueHint>();
+    NodeInput input = btn->property("input").value<NodeInput>();
+
+    input.node()->SetValueHintForInput(input.input(), input.element(), hint);
+  }
+}
+
+}

app/widget/nodevaluetree/nodevaluetree.h

@@ -0,0 +1,32 @@
+#ifndef NODEVALUETREE_H
+#define NODEVALUETREE_H
+
+#include <QRadioButton>
+#include <QTreeWidget>
+
+#include "node/node.h"
+
+namespace olive {
+
+class NodeValueTree : public QTreeWidget
+{
+  Q_OBJECT
+public:
+  NodeValueTree(QWidget *parent = nullptr);
+
+  void SetNode(const NodeInput &input, const rational &time);
+
+protected:
+  virtual void changeEvent(QEvent *event) override;
+
+private:
+  void Retranslate();
+
+private slots:
+  void RadioButtonChecked(bool e);
+
+};
+
+}
+
+#endif // NODEVALUETREE_H

app/widget/nodeview/nodeview.h

@@ -79,6 +79,11 @@ public:
 
   void ZoomOut();
 
+  const QVector<Node*> &GetCurrentContexts() const
+  {
+    return filter_nodes_;
+  }
+
 public slots:
   void SetMiniMapEnabled(bool e)
   {