From 313f5ef0c7b30b64c264c7a332297ebb2d3d77c2 Mon Sep 17 00:00:00 2001
From: Geoff Hutchison <geoff.hutchison@gmail.com>
Date: Fri, 8 May 2015 19:19:14 -0400
Subject: [PATCH] Add distance label while drawing occurs for immediate
 feedback.

Gives the bond distance between the atoms.

Change-Id: Ia26ea632a4a32fd63d6c495f7b74206ca60949d5
---
 avogadro/qtplugins/editor/editor.cpp | 54 +++++++++++++++++++++++++++-
 avogadro/qtplugins/editor/editor.h   |  5 +++
 2 files changed, 58 insertions(+), 1 deletion(-)

diff --git a/avogadro/qtplugins/editor/editor.cpp b/avogadro/qtplugins/editor/editor.cpp
index f451fa1d9..a1a58c0ee 100644
--- a/avogadro/qtplugins/editor/editor.cpp
+++ b/avogadro/qtplugins/editor/editor.cpp
@@ -31,6 +31,13 @@
 
 #include <avogadro/rendering/camera.h>
 #include <avogadro/rendering/glrenderer.h>
+#include <avogadro/rendering/geometrynode.h>
+
+#include <avogadro/rendering/groupnode.h>
+#include <avogadro/rendering/textlabel2d.h>
+#include <avogadro/rendering/textlabel3d.h>
+#include <avogadro/rendering/textproperties.h>
+
 
 #include <QtWidgets/QAction>
 #include <QtWidgets/QComboBox>
@@ -57,9 +64,15 @@ using QtGui::RWAtom;
 using QtGui::RWBond;
 using QtGui::Molecule;
 using QtGui::RWMolecule;
-using Rendering::Identifier;
 using QtOpenGL::GLWidget;
 
+using Avogadro::Rendering::GeometryNode;
+using Avogadro::Rendering::GroupNode;
+using Avogadro::Rendering::Identifier;
+using Avogadro::Rendering::TextLabel2D;
+using Avogadro::Rendering::TextLabel3D;
+using Avogadro::Rendering::TextProperties;
+
 Editor::Editor(QObject *parent_)
   : QtGui::ToolPlugin(parent_),
     m_activateAction(new QAction(this)),
@@ -208,6 +221,36 @@ void Editor::adjustHydrogens()
   }
 }
 
+void Editor::draw(Rendering::GroupNode &node)
+{
+  if (fabs(m_bondDistance) < 0.3)
+    return;
+
+  GeometryNode *geo = new GeometryNode;
+  node.addChild(geo);
+
+  // Determine the field width. Negate it to indicate left-alignment.
+  QString distanceLabel = tr("Distance:");
+  int labelWidth = -1*distanceLabel.size();
+
+  QString overlayText = QString("%1 %L2")
+    .arg(tr("Distance:"), labelWidth)
+    .arg(m_bondDistance, 10, 'f', 3);
+
+  TextProperties overlayTProp;
+  overlayTProp.setFontFamily(TextProperties::Mono);
+  overlayTProp.setColorRgb(64, 255, 220);
+  overlayTProp.setAlign(TextProperties::HLeft, TextProperties::VBottom);
+
+  TextLabel2D *label = new TextLabel2D;
+  label->setText(overlayText.toStdString());
+  label->setTextProperties(overlayTProp);
+  label->setRenderPass(Rendering::Overlay2DPass);
+  label->setAnchor(Vector2i(10, 10));
+
+  geo->addDrawable(label);
+}
+
 void Editor::updatePressedButtons(QMouseEvent *e, bool release)
 {
   /// @todo Use modifier keys on mac
@@ -226,6 +269,9 @@ void Editor::reset()
   m_pressedButtons = Qt::NoButton;
   m_clickedAtomicNumber = INVALID_ATOMIC_NUMBER;
   m_bondAdded = false;
+
+  m_bondDistance = 0.0f;
+  emit drawablesChanged();
 }
 
 void Editor::emptyLeftClick(QMouseEvent *e)
@@ -449,6 +495,12 @@ void Editor::atomLeftDrag(QMouseEvent *e)
     Vector3f newPos = m_renderer->camera().unProject(windowPos, oldPos);
     newAtom.setPosition3d(newPos.cast<double>());
     changes |= Molecule::Atoms | Molecule::Modified;
+
+    RWAtom clickedAtom = m_molecule->atom(m_clickedObject.index);
+    if (clickedAtom.isValid()) {
+      Vector3f bondVector = clickedAtom.position3d().cast<float>() - newPos;
+      m_bondDistance = bondVector.norm();
+    }
   }
 
   m_molecule->emitChanged(changes);
diff --git a/avogadro/qtplugins/editor/editor.h b/avogadro/qtplugins/editor/editor.h
index b81463ac3..f88cc86a2 100644
--- a/avogadro/qtplugins/editor/editor.h
+++ b/avogadro/qtplugins/editor/editor.h
@@ -23,6 +23,7 @@
 #include <avogadro/core/avogadrocore.h>
 #include <avogadro/rendering/primitive.h>
 
+
 #include <QtCore/QPoint>
 
 namespace Avogadro {
@@ -72,6 +73,8 @@ class Editor : public QtGui::ToolPlugin
   QUndoCommand * mouseMoveEvent(QMouseEvent *e) AVO_OVERRIDE;
   QUndoCommand * keyPressEvent(QKeyEvent *e) AVO_OVERRIDE;
 
+  void draw(Rendering::GroupNode &node) AVO_OVERRIDE;
+
 private slots:
   void clearKeyPressBuffer() { m_keyPressBuffer.clear(); }
   void adjustHydrogens();
@@ -110,6 +113,8 @@ private slots:
   unsigned char m_clickedAtomicNumber;
   bool m_bondAdded;
   QString m_keyPressBuffer;
+
+  Real m_bondDistance;
 };
 
 } // namespace QtPlugins