JVCL Components

About

JVCL is a library of more than 600 Delphi visual and non-visual components (https://github.com/project-jedi/jvcl). Although heavily Windows-centered, some of them have been ported to Lazarus. This page intends to give a summary of the JVCL components available for Lazarus. Some of the info snippets were taken from http://wiki.delphi-jedi.org/wiki/JVCL_Component_Overview.

Packages

Due to the large number of components the original Delphi version is split into a variety of packages. The Lazarus port follows this convention because the user can install only the functionality needed.

For each package, a runtime and designtime version is available. Runtime packages can be identified with an appended R, designtime packages with an appended D. In the requirements for a project always use the runtime package.

JvCore

Provides basic functionality needed by all other packages.

JvStdCtrls

Depends on package JvCore.
Enhanced standard controls

• TJvCheckbox : Has a property LinkedControls. Linked controls can be enabled/disabled according to the Checked state of the Checkbox.
• TJvPanel : an extended panel with hot-tracking effects and automatic placement of child components (similar to LCL's ChildSizing property). Can be dragged and resize at runtime. See example project JvPanelDemo.
• JvCalcEdit : a numeric edit control which opens a calculator dialog.

JvCtrls

Depends on packages JvCore and JvStdCtrls.
Visual controls

• TJvBehaviorLabel : a label with special display effects: Blinking, bouncing, scrolling, typing, appearing, "special", "code breaker". See demo examples/JvBehaviorLabel.
• TJvMovableBevel : a bevel which can be dragged and resized at runtime
• TJvMovablePanel : the same, but now for a panel. Note that this component does not belong to JVCL, it is a simple adaption of TJvMovableBevel to the panel case.
• TJvRuler : a ruler to indicate distances in centimeters, inches or pixels
• TJvGroupHeader : header with attached bevelled line.
• TJvRollOut : expandable panel with headerline.
• TJvHtLabel , TJvHTCombobox , TJvHTListbox and TJvHint : a set of controls which can display HTML text

• TJvComboListBox : a listbox which can display a combobox overlaying the selected listbox item. Assign a TPopupMenu to the DropdownMenu property and it will be shown when the combo button is clicked. You can also handle the OnDropDown event for custom handling when the button is clicked, or example, displaying a drop down form. These features are demonstrated in the JvComboListBox example project.
• TJvOfficeColorPanel : a panel for color selection designed like the one used by Office 97.

• TJvLookupAutoComplete : adds autocompletion of TEdit by ListBox or StringList items. (In the original JVCL, this component is in the Core package.)

JvCustom

Depends on package JvCore
Custom components

• TJvValidateEdit : General purpose edit control for text and numbers (integer, float, currency). MaxValue, MinValue, HasMaxValue, HasMinValue - Value is corrected when Edit loses focus. See demo in JvValidateEdit.
• TJvTimeLine : a one-dimensional calendar ("time-line") which can display various events and tasks. See demo JvTimeLine.
• TJvTMTimeLine : another timeline component. See demo JvTMTimeLine.
• TJvGammaPanel : advanced color selection tool for foreground and background colors. See demo JvGammaPanel.
• TJvThumbView : displays a list of images as thumbnails
• TJvOutlookBar : an accordeon-like bar of containers for other controls as used by Outlook 97.
• TJvImagesViewer : displays a list of images as thumbnails, similar to TJvThumbView. See JvItemViewer demo.
• TJvImageListViewer : dispays all images of a TImageList. See JvItemViewer demo.
• TJvOwnerDrawViewer : presents arbitrary information in a grid-like view. See JvItemViewer demo.

• TJvChart : component for drawing time-series charts. Some bugs... See _JvChartDemo_ project. Removed: Incomplete, too many bugs.

JvCmp

Depends on package JvCore.
Non-visual components

• TJvStrHolder , TJvMultiStringHolder : a wrapper component making it easier to work with TStrings and TStringList at design time. Using TStrHolder component you can set TStrings properties and event handlers in form designer and hold a number of strings in your forms.
• TJvSpellChecker : a spell-checker class with sample dictionaries for English and Dutch. See demo in folder examples/JvSpellChecker of the JVCL installation.

• TJvProfiler : --- to be written ---

JvDB

Depends on packages JvCore , JvStdCtrls , and JvCtrls
Data-aware controls

• TJvSearchEdit : a TEdit with incremental search capabilities within a field of a dataset.
• TJvDBLookupList and TJbDBLookupCombo : lookup controls with additional features:
  • can display more than one column (the LookupDisplay property can contain a list of columns separated by a semicolon, the column width is calculated based on Field.DisplayWidth)
  • can display pictures (OnGetImage/OnGetImageIndex events)
  • configurable empty value (DisplayEmpty,EmptyItemColor,EmptyStrIsNull,EmptyValue)
• TJvDBTreeView : a treeview constructed from database records. Link the unique ID field to "MasterField", the ID field of the parent node to "DetailField", and the field with the node text to "ItemField". Optionally, the field "IconField" provides the image index for the ImageList. "StartMasterValue" is the beginning level to start building the TreeView, 0 = start from the root items, 1 = start from the second level, and so on.
• TJvDBCalcEdit : a numeric edit box which opens a calculator dialog.

https://upload.wikimedia.org/wikipedia/commons/d/d8/Nuvola_apps_ktip.png Note: The packages JvStdCtrlsLazR and JvCtrlsLazR must have been compiled before this package can be installed.

JvAppFrm

Depends on package JvCore
Components for applications and forms

• JvAppAnimatedIcon and JvFormAnimatedIcon : display an animated icon (created from an imagelist) in the taskbar and in the form's title bar, respectively.
• JvAnimTitle : provides an animated form title
• JvFormWallpaper : tiles the background of a form with an image.

JvHMI

Depends on package JVCore.
The packages JvHDMILazR (run time) and JvHDMILazD (design time) provide some components for designing a "human-machine-interface" (HMI).

• JvLED : an LED indicator. See demo examples/JvLED.
• JvDialButton : a rotatory knob. See demo examples/JvDialButton.

JvJans

Depends on package JvCore.
Named after the original author, Jan Verhoeven, who donated these components to the JEDI project. The following components have been ported:

• TJvSIM components: a set of components for simulation of digital and analog electronics.
• JvJanLED : an LED indicator component (not contained in original JVCL, ported from Jan Verhoeven's own repository).
• JvJanToggle : a toggle button with an on and off area (not contained in original JVCL, ported from Jan Verhoeven's own repository).
• JvMarkupViewer and JvMarkupLabel : display simple HTML-formatted text (font-related tags only). Similar to JvHTControls.
• TvGridFilter : a component for filtering rows in a column-oriented stringgrid. Call Filter(condition) to hide all rows meeting the specified condition string, e.g. [Business]="Music" removes all rows in which the strings in the column titled Business are equal to Music. Allowed operators are =, <>, <, >, or like. See demo in folder JvGridFilterDemo.
• JvYearGrid : a year-calendar

JvMM

Depends on package JvCore.
The original JVCL package for Delphi contains a set of multimedia components, image and some general-purpose components.

• JvID3v1 : a non-visual component for displaying and editing of ID3v1 tags of mp3 files. See demo examples/JvID3v1.
• JvID3v2 : a non-visual component for displaying and editing of ID3v2 tags of mp3 files. See demo examples/JvID3v2.
• JvAnimatedImage : animates a series of images take from a glyph containing all images in a horizontal or vertical stripe.
• JvBmpAnimator : animates a series of images taken from a TImagelist. Unlike suggested by its name, it works with other image types as well in Lazarus. See demo examples/JvBmpAnimator. Similar to JvAnimatedImage.
• JvImageTransform : image transition effects like in a simple slide show. See demo examples/JvImageTransform.
• JvSpecialImage : an advanced image component with simple built-in image manipulation capabilities (flip, mirror, invert, fade-in, fade-out, brightness). Note that the Brightness property has been modified from the Delphi version to cover a more convenient scale from -100 to 100 (instead of 0 to 200). See demo examples/JvSpecialImage.
• JvSpecialProgress : an advanced progress bar with gradient and text display. See demo examples/JvSpecialProgress.
• JvGradient : draws several kinds of gradients (horizontal, vertical, elliptic, pyramidic).
• JvGradientHeaderPanel : a header bar with a gradient background (drawn by JvGradient).
• JvFullColorLabel : a label with attached color sample
• JvFullColorDialog and JvFullColorCircleDialog : dialogs for color selection based on several color models. Use the JvFullColorTrackbar for one-dimensional, and a JvFullColorPanel and a JvFullColorCircle for two-dimensional color selection. There is also a swatch-like JvFullColorGroup. See demos examples/JvFullColorDialog and examples/JvFullColorCircleDialog. Similar to mbColorLib, however, several color models are combined within the same control.

• JvPicClip : similar to TImageList. Splices a large bitmap to a grid of Cols x Rows smaller images which can be retrieved as Cells[ACol, ARow]

JvPageComps

Depends on packages JvCore and JvStdCtrls

• TJvTabBar : a panel of tabs like in a TTabControl. Fully configurable. Drawing is delegated to separate painter components, TJvModernTabBarPainter (used by default) and TJvTabBarXPPainter. See demo in folder examples/JvTabBar.
• TJvPageList : a stack of pages like a TNotebook. Designed to cooperate with TJvTabBar and TJvPageListTreeView. See demo in folder examples/JvTabBar_PageList.
• TJvNotebookPageList : a TNotebook descendant designed to cooperate with TJvTabBar. See demo in folder examples/JvTabBar_NotebookPages. Note that this component is not contained in the original Delphi JVCL collection.
• TJvNavigationPane : a navigation panel similar to MS Outlook. See demo in the folder examples/JvNavigationPane of the Lazarus JVCL installation.

JvPascalInterpreter

Scripting engine for Pascal. Depends on package JvCore.

• TJvInterpreterProgram : Non-visual component interpreting Pascal code. Add code to the Pas Strings, execute if by the Run method and get the result from the VResult variant. See the tutorials in folder example/JvInterpreterDemos. There is also a (German) tutorial at 1(https://wiki.delphigl.com/index.php/Tutorial_Scripting_mit_JvInterpreterProgram).

JvRuntimeDesign

Depends on package JvCore.

• A runtime form designer. See demo in folder example/JvDesigner of the JVCL installation. Note that the designer is not limited to the components shown on the demo's toolbar. Following the instructions in the header of the demo's main unit it is easy to register any other component.

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JvTimeFramework

Depends on package JvCore. Calendars and schedule planner, similar to TvPlanIt. Can compare schedules of several persons.

• TJvTFScheduleManager : administration of data, access to database via events.
• TJvTFDays , TJvTFWeeks or TJvTFMonths are day, week or month calendars, respectively, to display appointments.
• TJvTFDaysPrinter : prints the appointments shown by TJvTFDays
• TJvTFGlanceTextViewer : viewing parameters for TJvTFWeeks and TJvTFMonths

See extended demo in examples/JvTimeFramework

JvValidators

Depends on package JvCore.
Various validator classes for input validataion. See demo in the folder examples/JvValidators of the Lazarus JVCL installation

• TJvErrorIndicator : Shows error indicators next to edit-fields etc. similar to "missing fields" indicators in web forumlars.
• TJvValidators : To validate user input. Rightclick on Field editor to define validation rules. Checks are performed when method "Validate" is called.

JvWizard

Depends on package JvCore.

• A multiplage dialog as used, e.g., for installation programs. Use the component editor to add pages with title, subtitle, images etc. at designtime ("welcome page", "interior page"). Buttons to navigate to other pages are automatically added. Additional navigation tools can be provided by adding a TJvWizardRouteMapSteps, TJvWizardRouteMapNodes, or TJvWizardRouteMapList component. See demo JvWizard.

JvXPCtrls

Depends on package JvCore and JvStdCtrls.
Several controls imitating the look and feel of Windows XP.

• JvXPButton and JvXPCheckbox : a button and a checkbox in XP-style
• TJvXPProgressBar : Draws a progressbar in XP-style. The color of the the background and of the blocks is configurable. Doesn't support Marquee-style.
• JvXPBar : a container side-bar with collapsable panels. Similar to TJvRollOut-Panel, but with string items instead of controls. Collapsing/Expanding happens smooth and nicely animated.

Download and installation

Download

The developers version of the Lazarus port is available via svn from https://sourceforge.net/p/lazarus-ccr/svn/HEAD/tree/components/jvcllaz/. The current release version can be downloaded from https://sourceforge.net/projects/lazarus-ccr/files/jvcllaz/; it is also offered by the Lazarus Online Package Manager.

Installation

• Released version distributed by the Online Package Manager: check the "jvcllaz" item in the Online Package manager, click the "Install" button and follow the instructions.
• Development version on Lazarus CCR (svn):
  • If you want to install all JVCL packages , load the package jvcl_all.lpk and select "Use" > "Install". In older Lazarus versions, there will be a warning "The package jvcl_all does not have any "Register" procedure which typically means it does not provide any IDE addon. Installing it will probably only increase the size of the IDE and may even make it unstable.". You can ignore this and click on "Install it, I like the fat".
  • If you want to install only a few packages , you must find out in above summary which other packages are needed. Compile the needed runtime packages (having an appended "R" at the package name). Then "Use" > "Install" the required designtime packages (having an appended "D" as the package name). It is required to rebuild the IDE only after the last package.

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From the Free Pascal wiki, page "JVCL Components", as the Internet Archive kept it on 2025-03-23, last changed on 2025-03-02. Copyright stays with the author who wrote it, according to the old wiki's Licensing page. If you have concerns about this material, message the admin.