HTLabel

Delphi HTML Label component

• Component Description
• Installing
• Component Properties
• Events
• Procedures/Functions
• Link Tag
• Tab Tag
• Transparency (why not?)
• Formatted Message Dialog Component

Component Description

This visual component allows you to specify a formatted text in a label, using almost the same sintax 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> - Aligh Right
<T:123> - Tab
<TF:123> - Tab with aligned break

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 specifyed by 6 digits, like in HTML notation. If you are getting color from Delphi, please remove the first two zeros of the begining of color code.

Installing

Open HTLabelPackage in Delphi. Then Build and Install.

Add sub-path "Lib" to the Library paths at Tools\Options.

Supports Delphi XE2..Delphi 10.3 Rio

Component Properties

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 specifyed at text or there is a value specifyed in MaxWidth property.

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

Color: TColor = Backgroud color of control

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

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

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

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

StyleLinkHover: THTStyleLinkProp = 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 eighter.

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

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

Events

procedure OnLinkEnter(Sender: TObject; LinkID: Integer; Target: String);

This event is fired when the mouse enters a link area

procedure OnLinkLeave(Sender: TObject; LinkID: Integer; Target: String);

This event is fired when the mouse leaves a link area

procedure OnLinkClick(Sender: TObject; LinkID: Integer; Target: String; 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; Target: String; 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).

Procedures/Functions

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 GetLinkTarget(LinkID: Integer): String;

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

function GetSelectedLinkTarget: String;

Returns the target string of selected link. A link is selected when the mouse is over it.

Link Tag

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 Target parameter.

Tab Tag

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.

Transparency (why not?)

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.

Formatted Message Dialog Component

Plase, 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: