DzHTMLText

• What's New
• Component Description
• Installing
• Component Properties
• Events
• Procedures/Functions
• Link Tag
• Image Tag
• Tab Tag
• Literal tag character
• Chinese/Japanese/Korean line break
• Transparency (why not?)
• Formatted Message Dialog Component

• 04/27/2020

  • Changed version to 1.2
  • Implemented OnRetrieveImgRes event to manually load images when using <imgres> tag.

• 04/26/2020

  • Included IMGRES tag, supporting PNG resource images.

• 04/10/2020

  • Support Chinese, Japanese and Korean line break - issue #8

• 03/09/2020

  • Fix AutoWidth bug using incorrect component Width - issue #7

• 03/01/2020

  • Add BeginUpdate/EndUpdate feature.
  • Move Rebuild procedure to public session.
  • Fix redundant call to rebuild on component bounds resized by auto properties.

• 02/15/2020

  • Add line vertical align property.
  • Add image support, based on ImageList. 🎨

• 06/03/2019

  • Lazarus support. Thanks to @jackdp. 😁

• 02/21/2019

  • Changed events to support Link display text. ⚠️

• 02/11/2019

  • Include auto install app

• 02/08/2019

  • Component renamed. Please full uninstall previous version before install this version. ⚠️

    The component was renamed because of other commercial component conflict.

• 02/07/2019

  • Add Win64 support (library folders changed!) ⚠️

This visual component allows you to specify a formatted text in a label, using almost the same syntax used in HTML code.

Here are all possible tags you can use in text:

<A[:abc]></A> - Link
<B></B> - Bold
<I></I> - Italic
<U></U> - Underline
<S></S> - Strike out
<FN:abc></FN> - Font Name
<FS:123></FS> - Font Size
<FC:clColor|$999999></FC> - Font Color
<BC:clColor|$999999></BC> - Background Color
<BR> - Line Break
<L></L> - Align Left
<C></C> - Align Center
<R></R> - Align Right
<T:123> - Tab
<TF:123> - Tab with aligned break
<IMG:nnn> - Image from ImageList where 'nnn' is image index
<IMGRES:name> - PNG image from Resource where 'name' is the resource name

The tags notation is case-insensitive, so you can use <B>Text</B> or <b>Text</b>.

Note about color notation: When you use FC or BC tags, the color in hexadecimal value is specified by 6 digits, like in HTML notation. If you are getting color from Delphi, please remove the first two zeros of the beginning of color code.

If you are using Lazarus: go to Package menu; Open Package File (.lpk); locate LazDzHTMLText.lpk; open the package; Compile it and Install it.

Close Delphi IDE and run CompInstall.exe app to auto install component into Delphi.

1. Open DzHTMLText package in Delphi.
2. Ensure Win32 Platform and Release config are selected.
3. Then Build and Install.
4. If you want to use Win64 platform, select this platform and Build again.
5. Add sub-path Win32\Release to the Library paths at Tools\Options using 32-bit option, and if you have compiled to 64 bit platform, add sub-path Win64\Release using 64-bit option.

Supports Delphi XE2..Delphi 10.3 Rio

AutoHeight: Boolean = Auto set height of control when Text property changed

AutoWidth: Boolean = Auto set width of control when Text property changed. If you are using AutoWidth, the text never wraps to a new line unless a line break is specified at text or there is a value specified in MaxWidth property.

AutoOpenLink: Boolean = Open links automatically on click over, without set event OnLinkClick. This property calls ShellExecute method.

Color: TColor = Background color of control

Font: TFont = Determines the base font. When no tag is specified on text, this base font is used.

Images: TCustomImageList = When using <img> tag, you should set this property to specify the ImageList where the images are stored.

Lines: Integer = Returns the total lines of text, according to the bounds of control. This property is read-only.

LineVertAlign: TDHLineVertAlign (vaTop, vaCenter, vaBottom) = Allows you to specify the vertical alignment of each element in the line. This property only take effects when the elements have different heights. Default is vaTop.

MaxWidth: Integer = Specify the maximum width of text, when using AutoWidth property.

StyleLinkNormal: TDHStyleLinkProp = Properties to format a link when is not selected by mouse.

StyleLinkHover: TDHStyleLinkProp = Properties to format a link when is selected by mouse.

Text: String = The text you want to show at label control. You can use <BR> tag to break lines. The Windows default Line Break (#13#10) breaks lines either.

TextHeight: Integer = Returns the total text height. This property is read-only.

TextWidth: Integer = Returns the total text width. This property is read-only.

procedure OnLinkEnter(Sender: TObject; LinkID: Integer; LinkData: TDHLinkData);

This event is fired when the mouse enters a link area

procedure OnLinkLeave(Sender: TObject; LinkID: Integer; LinkData: TDHLinkData);

This event is fired when the mouse leaves a link area

procedure OnLinkClick(Sender: TObject; LinkID: Integer; LinkData: TDHLinkData; var Handled: Boolean);

This event is fired when a link is left-clicked by the mouse. You can use Handled var to by-pass the AutoOpenLink property (the handled value is False at method start).

procedure OnLinkRightClick(Sender: TObject; LinkID: Integer; LinkData: TDHLinkData; var Handled: Boolean);

This event is fired when a link is right-clicked by the mouse. You can use Handled var to by-pass the AutoOpenLink property (the handled value is False at method start).

procedure OnRetrieveImgRes(Sender: TObject; const ResourceName: String; Picture: TPicture; var Handled: Boolean);

If you are using <imgres> tag, this event will fire on every image tag, allowing you to manually load a image from anywhere, in any image format, assigning it to Picture object. Be sure to set Handled := True when you manually load an image. Not using this event causes the component to automatically load the image from application resources by name, and must be in PNG format.

Example:

procedure TForm1.DzHTMLText1RetrieveImgRes(Sender: TObject; const ResourceName: string;
  Picture: TPicture; var Handled: Boolean);
var JPG: TJpegImage;
begin
  if ResourceName='TEST' then
  begin
    JPG := TJpegImage.Create;
    try
      JPG.LoadFromFile('C:\Test.jpg');
      Picture.Assign(JPG);
    finally
      JPG.Free;
    end;

    Handled := True; 
  end;
end;

function IsLinkHover: Boolean;

This function returns true when the mouse is over a link

function SelectedLinkID: Integer;

This function returns the ID of the selected link. This ID is auto generated according by the links sequence in the text. The ID is used to get the target string, that is stored in a internal TStringList.

function GetLinkData(LinkID: Integer): TDHLinkData;

Returns TDHLinkData object of the link id. The ID is auto generated according by the links sequence in the text.

function GetSelectedLinkData: TDHLinkData;

Returns TDHLinkData object of the selected link. A link is selected when the mouse is over it.

procedure Rebuild;

This method rebuilds all internal text elements to get component ready to paint. Call this method if you want to get some calculated property, like TextWidth and TextHeight. Otherwise, you don't need to call this procedure directly.

procedure BeginUpdate;

Increments internal update semaphore, so while reference counting is bigger than zero, the component will not repaint automatically when the properties are changed, like changing Text or Font property.

procedure EndUpdate(ForceRepaint: Boolean = True);

Decrements internal update semaphore, so when reference counting is zero, if ForceRepaint parameter is True, then the component will repaint the HTML Text.

BeginUpdate/EndUpdate example:

DzHTMLText1.BeginUpdate;
try
  DzHTMLText1.Text := 'Text <b>test</b> 1234';
  DzHTMLText1.Font.Color := clRed;
  DzHTMLText1.Font.Size := 20;
finally
  DzHTMLText1.EndUpdate;
end;

There are two ways to use link tag:

1. Declaring internal link and the text do display:

   <a:www.google.com>Open Google Search</a>

   This will display: Open Google Search

2. Just using the display text:

   <a>www.google.com</a>

   This will display: www.google.com

You can use any text as internal link code. Then you can handle this code at OnLinkClick / OnLinkRightClick / OnLinkEnter / OnLinkLeave events, reading LinkData parameter.

This object stores the information about a link.

Properties:

• Target: String = The link target specified at <a:target> tag

• Text: String = The link display text specified at <a:target>Display Text</a> tag

You can retrieve this object using OnLinkClick / OnLinkRightClick / OnLinkEnter / OnLinkLeave events. Also you can call GetLinkData or GetSelectedLinkData.

You can use the tags:

• <IMG:index> to show an image of a TImageList component. Just assign the Images property to the ImageList. Then use the index parameter to indicate the index of the image in the ImageList component.

• <IMGRES:name> to show an image of a PNG resource. Include PNG image into application resources and then use the name parameter to indicate the name of the resource. Important: the image will be displayed only at runtime.

Example:

In this example, the image tag should be <imgres:test>

There are two tab tags you can use:

• <t:nnn> = Allow you to positioning text exactly on "nnn" position in pixels starting on the left border of component. If the text wraps to a new line, it will be return aligned at left border of component.

• <tf:nnn> = The same as above, but if the text wraps to a new line, it will be aligned in the same position as the first line which the tab started. This tag will produce a better visual text alignment.

If you want to display characters < and > in the text, just type the HTML code:

• < = <
• > = >

If you have component width smaller than your text, then it will break to a new line according to some specific chars. These chars are: (space), \ and /. The bars are considered as word break because if you type some path, for example, then should be a way to split this path into a new line if it was too big.

When you type Chinese, Japanese or Korean characters, this behavior is quite different. In this case, the component will break lines considering any char as a complete word.

The transparency option is not available for this component, because the text painted on canvas is not static. This means the canvas needs to change eventually, when mouse is over links. So this causes a lot of flickering. Because of that, the transparency is not available at this time.

Please, take a look at my Message Dialogs Component that uses this HTML Component to display formatted messages. The component will make much more easy to manage your application messages.

https://github.com/digao-dalpiaz/Dam

Message Dialog Example: