DesignKit Package

DesignKit is a Lazarus package that provides a set of visual and non‑visual components to enhance application UI design.
All components are installed on the Common Controls tab of the component palette.

Requirements

• Lazarus (tested with 4.8) / Free Pascal Compiler 3.2.2 or newer.
• LCL – included with Lazarus.
• IDEIntf – included with Lazarus.
• Helpers – common utility units used by the spell‑checker (available in plainlib).
• Toolkit – general‑purpose utility classes (available in plainlib).
• Windows 8 or later is required only for the native WinSpellChecker backend. The HunSpell backend works on all platforms (Windows, Linux, macOS) and does not need any OS‑specific API.

---

TCalendarLite Modified (Common Controls )

TCalendarLite is a lightweight, resizable calendar component - a TGraphicControl descendant, so it has no native counterpart and behaves identically on Windows, Linux, and macOS. It is used in DesignKit as a drop-in replacement for the original Lazarus CCR calendar, extended with independent single/range selection, per-day events, mouse-wheel month navigation, and full localization.

The component draws a standard month grid with a header (month/year caption, navigation arrows), a row of weekday names, the six date rows, and an optional "today" footer row that shows the current day and the currently selected range.

Selection

Single and range selections are kept separately and do not interfere with each other. The rules are:

• Single click on a day toggles its single selection. Clicking the selected day again clears it. The range (if any) is left untouched.
• Shift+click builds a new range from the current single selection to the clicked cell. The anchor is fixed for the whole Shift-held sequence, so subsequent Shift+clicks keep extending from the original cell. Single selection jumps to the end of the range.
• Drag (press and move the mouse) builds a new range from the press cell to the release cell. While dragging, the single selection follows the mouse. Releasing on the same cell as the press does not create a range - it falls back to a plain single toggle.
• Double-click on the same cell: if a range exists, it is cleared; if not, a range is built from the single selection to the clicked cell (or just sets the single selection if nothing was selected). Rapid double-clicks that hit different cells are treated as two plain clicks, which guards against false double-clicks after view navigation.
• Arrow keys move the single selection; Shift+arrow extends the range from the current anchor.
• A range always contains at least two days; attempting to narrow it to one cell simply removes the range.
• Mouse wheel scrolls the view to the previous/next month without touching the current selection. The scroll rate is throttled so the grid moves at a comfortable pace.

Events

Each day can carry any number of user events. An event is a date, a caption, and a colour; events are displayed as small coloured squares under the day number and can be clicked individually.

Calendar.Events.Add(Now, 'Pay bills', clRed);

Colors

All drawing colours are exposed through the Colors: TCalColors sub-property. The most relevant entries are SelectedDateColor (single selection), SelectedRangeColor (range), TodayFrameColor, and EventFocusColor (hovered event square).

Localization

The Languages property switches day names, month names, and format strings between the built-in languages (lgEnglish, lgFrench, lgGerman, lgHebrew, lgSpanish, lgItalian, lgPolish, lgFinnish, lgGreek, lgRussian). Use lgCustom together with DayNames, MonthNames, and DisplayTexts to supply your own.

Key Properties

Property	Default	Description
Date	Now	Currently focused date.
MultiSelect	False	Enables multi-select mode (range, Shift/drag, etc.).
Languages	lgEnglish	Built-in localization preset.
Options	see code	Set of TCalOption flags: today frame/row, weekends, holidays, borders, etc.
Colors	see code	All drawing colours (see TCalColors).
Events	empty	User event list (TCalEventList).
StartingDayOfWeek	dowSunday	First column of the week.
WeekendDays	[dowSunday]	Days rendered with the weekend colour.
ButtonWidth / ButtonHeight	0	Arrow button sizes (0 = auto).
EventSquareSize	6	Side length of the event marker square.
EventSquareBottom	5	Bottom margin for event markers.
DayNames, MonthNames, DisplayTexts	empty	Custom strings used with lgCustom.

Key Events

Event	Description
OnDateChange	Fired when the focused date changes.
OnMonthChange	Fired when the focused month changes (view navigation).
OnRangeSelected	Fired when a multi-day range is created or cleared.
OnEventClick	Fired when a user event square is clicked.
OnGetHolidays	Supply per-month holidays as a bit mask.
OnGetDayText	Override the day-number caption.
OnPrepareCanvas	Adjust the canvas per cell before drawing.
OnDrawCell	Fully custom-draw a day cell.
OnHint	Provide a hint for a day under the mouse.

Notes on this fork

The component originates from the Lazarus CCR (Community Components Repository) and is bundled with DesignKit in a modified form. All DesignKit-specific changes (independent single/range selection, events, mouse-wheel navigation, localization presets, colour extensions, and the today-row range display) are tracked in the project git history: https://github.com/plainlib/designkit. The original license and authorship are preserved below.

TCalendarLite license

TCalendarLite is free software distributed under the GNU Library General Public License, version 2 or later, with a special linking exception that permits linking it with independent modules. The original license notice from the component's source header is reproduced below as required by its terms:

{ TCalendarLite is a lightweight calendar component, a TGraphiccontrol descendant, which is consequently not dependent on any widgetset. It is not a fixed-size component, as are most calendars, but will align and resize as needed

Originator : H Page-Clark, 2013/2016 Contributions : Ariel Rodriguez, 2013 Werner Pamler, 2013/2016 John Greetham, 2016

This library is free software; you can redistribute it and/or modify it under the terms of the GNU Library General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version with the following modification:

As a special exception, the copyright holders of this library give you permission to link this library with independent modules to produce an executable, regardless of the license terms of these independent modules,and to copy and distribute the resulting executable under terms of your choice, provided that you also meet, for each linked independent module, the terms and conditions of the license of that module. An independent module is a module which is not derived from or based on this library. If you modify this library, you may extend this exception to your version of the library, but you are not obligated to do so. If you do not wish to do so, delete this exception statement from your version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License for more details.

You should have received a copy of the GNU Library General Public License along with this library; if not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

Modified by Alexander Tverskoy (plaintool), 2026. All changes are tracked in the project git history: https://github.com/plainlib/designkit }

---

TFormGrip (Common Controls )

TFormGrip is a visual control that draws a size grip in a selected corner of its parent (a form or a panel) and resizes that parent when the grip is dragged. It behaves like the grip found in a StatusBar, but can be placed in any corner and styled freely.

The component does not hook or override any events of its parent. All mouse handling, painting, and resizing are performed inside the control itself, so the parent form's own OnPaint, OnMouseDown, OnMouseMove, OnMouseUp, and OnResize handlers remain untouched.

Features

• Works with any TWinControl parent, not only with forms.
• Grip can be placed in any of the four corners of the parent.
• The control automatically snaps to the chosen corner and cannot be moved away from it; resizing or repositioning the parent keeps the grip in place.
• Multiple grip drawing styles: dots (triangular arrangement), lines, grid, or solid triangle.
• Background can either follow the parent colour (ParentColor = True, the default) or use its own Color.
• Two independent offsets, named after the CSS box model: GripMargin moves the whole control away from the parent corner, while GripPadding insets the drawn pattern inside the control.
• Resizing respects configurable minimum parent width and height.
• Double buffered painting with csOpaque, so the grip redraws cleanly during parent resize without flicker or black artefacts.
• In design time the grip is drawn but does not resize the parent.

Key Properties

Property	Default	Description
Visible	True	Shows or hides the grip.
ShowGrip	True	Controls drawing of the grip pattern.
GripCorner	gcBottomRight	Corner of the parent: gcBottomRight, gcBottomLeft, gcTopRight, or gcTopLeft.
GripMargin	0	Outer offset - distance between the control and the parent's corner (in pixels).
GripPadding	2	Inner offset - distance between the control's edge and the drawn pattern (in pixels).
GripColor	clActiveBorder	Colour used to draw the grip pattern.
GripStyle	gsDots	Drawing style: gsDots, gsLines, gsGrid, or gsSolid.
DotSize	2	Size of the dots (for gsDots and gsGrid).
DotSpacing	3	Distance between dots.
MinParentWidth	100	Minimum parent width allowed during resizing.
MinParentHeight	100	Minimum parent height allowed during resizing.
ParentColor	True	When True, background follows Parent.Color; otherwise uses Color.
Color	clBtnFace	Background colour used when ParentColor is False.
Width, Height	16, 16	Size of the grip control in pixels.

Usage

1. Drop a TFormGrip component from the Common Controls palette onto a form or a panel.
2. Choose the desired corner using GripCorner and adjust the remaining properties in the Object Inspector.
3. At runtime the grip appears in the selected corner and resizes its parent when dragged.

Example code to create and configure TFormGrip at runtime:

var
  Grip: TFormGrip;
begin
  Grip := TFormGrip.Create(Self); // Self is the parent control
  Grip.Parent := Self;
  Grip.GripCorner := gcBottomRight;
  Grip.GripStyle := gsLines;
  Grip.GripColor := clGray;
  Grip.GripMargin := 0;
  Grip.GripPadding := 3;
  Grip.Width := 16;
  Grip.Height := 16;
end;

Class hierarchy

The component is split into two classes following the standard Lazarus convention:

• TCustomFormGrip - base class that implements all behaviour. Inherit from it to create custom variants with your own published properties.
• TFormGrip - ready-to-use component that publishes the most useful properties of TCustomFormGrip and of the inherited TControl.

---

TFlatButton (Common Controls )

TFlatButton is a custom TSpeedButton descendant that always draws a flat, themed button (similar to toolbar buttons) and provides integrated tooltip support with extensive customisation.

Features

• Always flat (inherited Flat property is hidden and forced to True).
• Uses the native theme (via ThemeServices) for normal, hot, and pressed states.
• Can optionally disable the pressed state drawing (DrawPressed).
• Allows vertical offset of the caption relative to the icon (OffsetY).
• Built‑in tooltip system with delay, size, colour, and auto‑hide duration.
• Tooltips are displayed using TOneShotTooltip and automatically hide when the button is clicked or the tooltip is dismissed.

Key Properties

Property	Default	Description
DrawPressed	True	If False, the button never appears pressed (visual state is always normal or hot).
OffsetY	0	Vertical pixel offset for the caption relative to the centre of the icon (positive moves text down).
Tooltip	''	The tooltip text to display (translatable caption).
TooltipDelay	0	Delay in milliseconds before the tooltip appears after a click (0 = immediate).
TooltipWidth	0	Width of the tooltip window (0 = auto‑size).
TooltipHeight	0	Height of the tooltip window (0 = auto‑size).
TooltipColor	clDefault	Background colour of the tooltip (clDefault uses system default).
TooltipDuration	0	Time in milliseconds after which the tooltip auto‑hides (0 = no auto‑hide).

Usage

Place a TFlatButton on a form, set an Images or Glyph for the icon, adjust Caption, and configure the tooltip properties.

Example:

var
  Btn: TFlatButton;
begin
  Btn := TFlatButton.Create(Self);
  Btn.Parent := Self;
  Btn.Caption := 'Save';
  Btn.ImageIndex := 0; // assume an ImageList assigned
  Btn.Tooltip := 'Save the current document';
  Btn.TooltipDelay := 500;
  Btn.TooltipDuration := 3000;
  Btn.OffsetY := 2; // move text slightly down
end;

---

Installation

1. Open the package file (designkit.lpk) in Lazarus.
2. Click Use → Install.
3. Rebuild the IDE.

The components will appear on the Common Controls tab of the component palette.

Licensing

DesignKit as a whole is distributed under the MIT License - see LICENSE.

The module src/calendarlite.pas and the resource src/calendarlite_icon.res are third-party code from the Lazarus CCR TCalendarLite component and are distributed under the Modified LGPL (with linking exception), the same license as the Lazarus LCL:

• Linking exception: LICENSE.CalendarLite.txt
• Full LGPL v2 text: COPYING.LGPL.txt
• Original authors' notice: README.CalendarLite.txt

The linking exception permits using these files together with MIT-licensed code without affecting the licensing of the rest of DesignKit.

---

DesignKit Package © 2026 by Alexander Tverskoy
Licensed under the MIT License – see the individual source files for details.