Get character position and select in Web browser control on mouse hover event

Hi,

Thanks for the reply's. I was out of station to visit my native place thsu why I can't able to give reply.
Anyway we required this tag html files to manage and the only issue is click and double click events.

Please suggest the solution for this issue.

Check again. I will be very surprised if it is true that "documents which are displayed using an underlined font are treated by the web browser control as a series of links". A WebBrowser control uses the same window and document libraries that IE uses for browsing web sites. Use of an underlined font as a hyperlink would be such a violation of HTML that blatant non-standard behavior such as that would be well known. Think about it; there is no way to determine the address ("href") when there is simply text using an underlined font.

Something else I will be very surprised if it is true is that you are not frustrated. I expect significant frustration with something such as this. The DOM and related software is cryptic and kludgy. The documentation is poor and many answers seem to be intentionally kept secret. There are a few things that I have tried doing that are supposed to work but no one can tell me why it does not. As far as Microsoft is concerned, what I have tried is supposed to work but it does not. There is one or two I should post here in a C# Corner forum to get at least confirmation that I am doing it as documented.

Hi,

The problem is not with the MouseHOver event, the problem is with the Click and DoubleClick events of the Web browser document.
The problem come for that files is when we set the

wbDocument.AllowNavigation =

false;

Sorry I have attached html file but it takes only Zip or Rar files. Please find the attachment for problem html files.

And for the attachment html files one is s20210fulltext.html and for this the performance issue come because of below steps in DocumentCompleted Event

                        wordElements = new List();
                        HtmlElementCollection spanElements = wbDocument.Document.Body.GetElementsByTagName("SPAN");

                        foreach (HtmlElement spanElement in spanElements)
                        {
                            if (spanElement.InnerText != null && spanElement.Children.Count == 0 && regWord.IsMatch(spanElement.InnerText))
                            {
                                wordElements.Add(spanElement);
                            }
                        }

Hi,

Sorry for that, Please find the attachment for the same.

For this issue when we set

wbDocument.AllowNavigation =

false; in the WebBrowser_DocumentCompleted event

Hi,

I have posted lot question to fullfil my requirement. But as you said I have tested a lot html files, every thing works fine but only one issue with one type of html file. Here I am attaching the html file for this the click and double click events are not working properly except every thing is working fine as my project requires.

Note that I looked at this thread a few times but I know it would take much more time than I have for this. This question is a big project. It should be many, many questions. The mouse hover question alone should be at least one separate question.

In HTML, there are elements in elements and at the lowest level there are text elements. I suspect that it is the contents of the text elements, and only text elements that are needed. If so then making that clear could significantly limit the work necessary to accomplish it.

I don't parse HTML using regular expressions. If it were me, I would sure look for a more precise solution.

Hi,

Did you get the issue which I am facing. Waiting for your reply, please send solution for this.

Hi,

But for me the firesafty also gives problem please check the attacted images the probelm.

Hi,

Thank you very much it is working perfect.

But only one small request the URI navigate is not working properly at my end after format the display content. Can you please recheck it once. I have upload images the difference and what we need along with the update code. Please look and solve this issue also.

Hi,

Thank you very much for your help and your quick reply.

Unfortunatly I am not able to find 100% solution regards this. Thus why what I required I have make sample application for your understand what i final required and uploading the code along with some screen shots which I am facing issues.

Please don't mind please look once and give proper solution.

OK, the good news is that I've managed to figure out how we can use tags rather than tags to make elements out of each word. The approach I've taken will work as long as all other tags in the document have either an 'id' or a 'style' attribute.

I've also changed things around so that loading the document from a uri now works properly in all circumstances.

There was a bug before in this part of the text:

   "sample paragraph 2
Foutheen You can also format"

Because there's no full stop after '2', the regular expression was giving '2Foutheen' as a single word when the tags were removed. To deal with this I've replaced all the
tags with '\n' which counts as a character and the regular expression now correctly gives two words '2' and 'Foutheen'.

As far as the DoubleClick event is concerned, there's no way to suppress the Click event from firing first because this will fire as soon as the mouse goes down, so you'll just have to find a way to work around that.

If a single click is highlighting a word but a double click is highlighting a whole sentence including that word, then I can't really see why there's any conflict.

Anyway here's the revised code - I haven't done anything for the click events as you seem to have something worked out already:

    public partial class frmWebBrowser : Form
    {
        #region Private Variables
       
        private MatchCollection mc;
        private List wordElements;
        private bool bindThroughUri;
        Point mouseHoverClientPosition = new Point();
        Point clickClientPosition = new Point();

        #endregion

        #region .ctor

        public frmWebBrowser()
        {
            InitializeComponent();
        }

        #endregion

        #region Handle Form Events

        private void frmWebBrowser_Load(object sender, EventArgs e)
        {
            cmbHtmlFiles.Items.Add("-- Select --");
            cmbHtmlFiles.Items.Add("fire_safety.html");
            cmbHtmlFiles.Items.Add("My cat called Lucky.html");
            cmbHtmlFiles.Items.Add("Alice in Wonderland.html");
            cmbHtmlFiles.SelectedIndex = 0;
        }

        #endregion

        #region Webbrowser Events

        private void wbDocument_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)
        {
            if (bindThroughUri)
            {
                bindThroughUri = false;
                if (chkFormat.Checked)
                {
                    wbDocument.DocumentText = FormatText(wbDocument.DocumentText);
                    return; // DocumentCompleted eventhandler will be re-entered
                }
            }

            // get all elements with no 'id' attribute
            wordElements = new List();
            HtmlElementCollection spanElements = wbDocument.Document.GetElementsByTagName("SPAN");

            foreach (HtmlElement spanElement in spanElements)
            {
                if (spanElement.Id == null && spanElement.Style == null)
                {
                    wordElements.Add(spanElement);
                }
            }

            // We need to change the font according to the User Selection thus why this line.
            wbDocument.Document.Body.Style = "font-size:18px;";
            wbDocument.Document.MouseOver += new HtmlElementEventHandler(Document_MouseOver);
            wbDocument.Document.Click += new HtmlElementEventHandler(Document_Click);
            wbDocument.Document.Body.AttachEventHandler("ondblclick", Document_DoubleClick);          
        }

        private void Document_DoubleClick(object sender, EventArgs e)
        {

        }

        void Document_MouseOver(object sender, HtmlElementEventArgs e)
        {
            mouseHoverClientPosition = e.ClientMousePosition;
            RetrieveWord();
        }

        void Document_Click(object sender, HtmlElementEventArgs e)
        {
            clickClientPosition = e.ClientMousePosition;          
        }

        #endregion

        #region Hanlde Click Events

        private void btnLoadText_Click(object sender, EventArgs e)
        {
            string text = "..."; // abbreviated for posting
            text = FormatText(text);
            bindThroughUri = false;
            wbDocument.DocumentText = text;
        }
       
        private void cmbHtmlFiles_SelectedIndexChanged(object sender, EventArgs e)
        {
            if (cmbHtmlFiles.SelectedIndex > 0)
            {
                BindThroughURI();
            }
        }

        private void chkFormat_CheckedChanged(object sender, EventArgs e)
        {
            if (cmbHtmlFiles.SelectedIndex > 0) // make sure a file is selected
            {
                BindThroughURI();
            }
        }

        private void btnUnFormat_Click(object sender, EventArgs e)
        {
            string text = "..."; // abbreviated for posting
            bindThroughUri = false;
            wbDocument.DocumentText = text;
        }

        #endregion

        #region Helper Methods
       
        private string FormatText(string text)
        {
            string text2 = Regex.Replace(text, @"", "\n"); // replace
tags with new line characters
            text2 = Regex.Replace(text2, "<.*?>", ""); // remove all remaining tags            
            string pattern = @"(?=/])"; // match words which are not in tags
            string replacement = "$0";
            mc = Regex.Matches(text2, @"\b\w+\b");  // match all words in text2
            text = Regex.Replace(text, pattern, replacement);  // surround words in text with tags
            return text;
        }

        private void RetrieveWord()
        {
            HtmlElement element = wbDocument.Document.GetElementFromPoint(mouseHoverClientPosition);
            string word = element.InnerText;


            if (!word.Contains(" ") && element.TagName == "SPAN" && element.Id == null && element.Style == null)
            {
                int index = -1;
               
                for (int i = 0; i < wordElements.Count; i++)
                {
                    if (wordElements[i].Equals(element))
                    {
                        index = i;
                        break;
                    }
                }
                txtMouseHoverWord.Text = String.Format("{0} : {1}", mc[index].Index, word);
            }
            else
            {
                txtMouseHoverWord.Text = ""; // show nothing otherwise
            }
        }
   
        private void BindThroughURI()
        {
            string folderPath = Path.Combine(Application.StartupPath, "Files");
            string filePath = Path.Combine(folderPath, cmbHtmlFiles.SelectedItem.ToString());           
            bindThroughUri = true;
            wbDocument.Navigate(new Uri(filePath));                      
        }

        #endregion
    }