Support text selection

PdfiumViewer.Demo/MainForm.cs

@@ -19,6 +19,8 @@ public MainForm()
 
             renderToBitmapsToolStripMenuItem.Enabled = false;
 
+            pdfViewer1.Renderer.ContextMenuStrip = pdfViewerContextMenu;
+
             pdfViewer1.Renderer.DisplayRectangleChanged += Renderer_DisplayRectangleChanged;
             pdfViewer1.Renderer.ZoomChanged += Renderer_ZoomChanged;
 
@@ -378,5 +380,20 @@ private void printMultiplePagesToolStripMenuItem_Click(object sender, EventArgs
                 form.ShowDialog(this);
             }
         }
+
+        private void copyToolStripMenuItem_Click(object sender, EventArgs e)
+        {
+            pdfViewer1.Renderer.CopySelection();
+        }
+
+        private void selectAllToolStripMenuItem_Click(object sender, EventArgs e)
+        {
+            pdfViewer1.Renderer.SelectAll();
+        }
+
+        private void pdfViewerContextMenu_Opening(object sender, CancelEventArgs e)
+        {
+            copyToolStripMenuItem.Enabled = pdfViewer1.Renderer.IsTextSelected;
+        }
     }
 }

PdfiumViewer.Demo/MainForm.resx

@@ -307,4 +307,7 @@
   <metadata name="statusStrip1.TrayLocation" type="System.Drawing.Point, System.Drawing, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
     <value>237, 17</value>
   </metadata>
+  <metadata name="pdfViewerContextMenu.TrayLocation" type="System.Drawing.Point, System.Drawing, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
+    <value>353, 17</value>
+  </metadata>
 </root>

PdfiumViewer.Demo/PdfRangeDocument.cs

@@ -288,6 +288,26 @@ public Rectangle RectangleFromPdf(int page, RectangleF rect)
             return _document.RectangleFromPdf(TranslatePage(page), rect);
         }
 
+        public int GetCharacterIndexAtPosition(PdfPoint location, double xTolerance, double yTolerance)
+        {
+            return _document.GetCharacterIndexAtPosition(location, xTolerance, yTolerance);
+        }
+
+        public bool GetWordAtPosition(PdfPoint location, double xTolerance, double yTolerance, out PdfTextSpan span)
+        {
+            return _document.GetWordAtPosition(location, xTolerance, yTolerance, out span);
+        }
+
+        public int CountCharacters(int page)
+        {
+            return _document.CountCharacters(page);
+        }
+
+        public List<PdfRectangle> GetTextRectangles(int page, int startIndex, int count)
+        {
+            return _document.GetTextRectangles(page, startIndex, count);
+        }
+
         private int TranslatePage(int page)
         {
             if (page < 0 || page >= PageCount)

PdfiumViewer/CustomScrollControl.cs

@@ -94,7 +94,8 @@ public override Rectangle DisplayRectangle
 
         public CustomScrollControl()
         {
-            SetStyle(ControlStyles.ContainerControl, true);
+            SetStyle(ControlStyles.Selectable, true);
+            SetStyle(ControlStyles.UserMouse, true);
             SetStyle(ControlStyles.AllPaintingInWmPaint, false);
 
             _horizontalScroll = new ScrollProperties(this, NativeMethods.SB_HORZ);

PdfiumViewer/IPdfDocument.cs

@@ -252,5 +252,38 @@ public interface IPdfDocument : IDisposable
         /// <param name="rect">The rectangle to convert.</param>
         /// <returns>The converted rectangle.</returns>
         Rectangle RectangleFromPdf(int page, RectangleF rect);
+
+        /// <summary>
+        /// Get the character index at or nearby a specific position. 
+        /// </summary>
+        /// <param name="location">The location to inspect</param>
+        /// <param name="xTolerance">An x-axis tolerance value for character hit detection, in point unit.</param>
+        /// <param name="yTolerance">A y-axis tolerance value for character hit detection, in point unit.</param>
+        /// <returns>The zero-based index of the character at, or nearby the point specified by parameter x and y. If there is no character at or nearby the point, it will return -1.</returns>
+        int GetCharacterIndexAtPosition(PdfPoint location, double xTolerance, double yTolerance);
+
+        /// <summary>
+        /// Get the full word at or nearby a specific position
+        /// </summary>
+        /// <param name="location">The location to inspect</param>
+        /// <param name="xTolerance">An x-axis tolerance value for character hit detection, in point unit.</param>
+        /// <param name="yTolerance">A y-axis tolerance value for character hit detection, in point unit.</param>
+        /// <param name="span">The location of the found word, if any</param>
+        /// <returns>A value indicating whether a word was found at the specified location</returns>
+        bool GetWordAtPosition(PdfPoint location, double xTolerance, double yTolerance, out PdfTextSpan span);
+
+        /// <summary>
+        /// Get number of characters in a page.
+        /// </summary>
+        /// <param name="page">The page to get the character count from</param>
+        /// <returns>Number of characters in the page. Generated characters, like additional space characters, new line characters, are also counted.</returns>
+        int CountCharacters(int page);
+
+        /// <summary>
+        /// Gets the rectangular areas occupied by a segment of text
+        /// </summary>
+        /// <param name="page">The page to get the rectangles from</param>
+        /// <returns>The rectangular areas occupied by a segment of text</returns>
+        List<PdfRectangle> GetTextRectangles(int page, int startIndex, int count);
     }
 }

PdfiumViewer/NativeMethods.Pdfium.cs

@@ -4,6 +4,7 @@
 using System.Text;
 using System.Windows.Forms;
 using System.IO;
+using System.Drawing;
 
 #pragma warning disable 1591
 
@@ -290,6 +291,17 @@ public static void FPDFText_GetCharBox(IntPtr page, int index, out double left,
             }
         }
 
+        public static int FPDFText_GetCharIndexAtPos(IntPtr page, double x, double y, double xTolerance, double yTolerance)
+        {
+            lock (LockString)
+            {
+                var idx = Imports.FPDFText_GetCharIndexAtPos(page, x, y, xTolerance, yTolerance);
+                if (idx == -3)
+                    throw new PdfException((PdfError)Imports.FPDF_GetLastError());
+                return idx;
+            }
+        }
+
         public static int FPDFText_CountChars(IntPtr page)
         {
             lock (LockString)
@@ -298,6 +310,40 @@ public static int FPDFText_CountChars(IntPtr page)
             }
         }
 
+        public static List<PdfRectangle> FPDFText_GetRectangles(IntPtr page, int pageIndex, int startIndex, int characterCount)
+        {
+            lock (LockString)
+            {
+                // GetRect uses internal state set by CountRects, so we should call them within the same lock
+
+                var count = Imports.FPDFText_CountRects(page, startIndex, characterCount);
+                var rectangles = new List<PdfRectangle>(count);
+
+                for (int i = 0; i < count; i++)
+                {
+                    if (!Imports.FPDFText_GetRect(page, i, out var left, out var top, out var right, out var bottom))
+                        throw new PdfException((PdfError)Imports.FPDF_GetLastError());
+
+                    rectangles.Add(new PdfRectangle(pageIndex, new RectangleF(
+                        (float)left,
+                        (float)top,
+                        (float)(right - left),
+                        (float)(bottom - top)
+                    )));
+                }
+
+                return rectangles;
+            }
+        }
+
+        public static char FPDFText_GetUnicode(IntPtr page, int index)
+        {
+            lock (LockString)
+            {
+                return Imports.FPDFText_GetUnicode(page, index);
+            }
+        }
+
         public static bool FPDFText_FindNext(IntPtr handle)
         {
             lock (LockString)
@@ -696,9 +742,21 @@ private static class Imports
             [DllImport("pdfium.dll")]
             public static extern void FPDFText_GetCharBox(IntPtr page, int index, out double left, out double right, out double bottom, out double top);
 
+            [DllImport("pdfium.dll")]
+            public static extern int FPDFText_GetCharIndexAtPos(IntPtr page, double x, double y, double xTolerance, double yTolerance);
+
             [DllImport("pdfium.dll")]
             public static extern int FPDFText_CountChars(IntPtr page);
 
+            [DllImport("pdfium.dll")]
+            public static extern int FPDFText_CountRects(IntPtr page, int startIndex, int count);
+
+            [DllImport("pdfium.dll")]
+            public static extern bool FPDFText_GetRect(IntPtr page, int index, out double left, out double top, out double right, out double bottom);
+
+            [DllImport("pdfium.dll", CharSet = CharSet.Unicode)]
+            public static extern char FPDFText_GetUnicode(IntPtr page, int index);
+
             [DllImport("pdfium.dll")]
             public static extern bool FPDFText_FindNext(IntPtr handle);
 

PdfiumViewer/PanningZoomingScrollControl.cs

@@ -120,6 +120,8 @@ public void ZoomOut()
         [DefaultValue(MouseWheelMode.PanAndZoom)]
         public MouseWheelMode MouseWheelMode { get; set; }
 
+        protected bool MousePanningEnabled { get; set; } = true;
+
         /// <summary>
         /// Raises the <see cref="E:System.Windows.Forms.Control.MouseWheel"/> event.
         /// </summary>
@@ -226,7 +228,7 @@ protected override bool IsInputKey(Keys keyData)
 
         protected override void OnSetCursor(SetCursorEventArgs e)
         {
-            if (_canPan && e.HitTest == HitTest.Client)
+            if (MousePanningEnabled && _canPan && e.HitTest == HitTest.Client)
                 e.Cursor = PanCursor;
 
             base.OnSetCursor(e);
@@ -243,7 +245,7 @@ protected override void OnMouseDown(MouseEventArgs e)
         {
             base.OnMouseDown(e);
 
-            if (e.Button != MouseButtons.Left || !_canPan)
+            if (!MousePanningEnabled || e.Button != MouseButtons.Left || !_canPan)
                 return;
 
             Capture = true;
@@ -255,7 +257,7 @@ protected override void OnMouseMove(MouseEventArgs e)
         {
             base.OnMouseMove(e);
 
-            if (!Capture)
+            if (!MousePanningEnabled || !Capture)
                 return;
 
             var offset = new Point(e.Location.X - _dragStart.X, e.Location.Y - _dragStart.Y);
@@ -267,7 +269,8 @@ protected override void OnMouseUp(MouseEventArgs e)
         {
             base.OnMouseUp(e);
 
-            Capture = false;
+            if (MousePanningEnabled)
+                Capture = false;
         }
 
         private class WheelFilter : IMessageFilter