EhLib
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Introduction

The Library is intended to increase capacity of the client’s part of the database application by improving interaction between application and users. 

 

Here is the list of the main components and classes of the Library. 

 

 
TDBGridEh component 

It provides all functionality of TDBGrid and adds several new features as follows:

  • Allows to select records, columns and rectangle areas.
  • Provides special titles that can cover several or all columns.
  • Can have a footer that is able to show sum/count/other field values.
  • Allows to resize column automatically to fit grid width equal to client width.
  • Has an ability to change row height and title height.
  • Allows automatic broken of a single line long title and data rows to a multiline.
  • Allows title to act as button and, optionally show a sort marker.
  • Allows to mark titles by sortmarking sings automatically and sort data in DataSet.
  • Allows to truncate long text with ellipsis in cells.
  • Allows lookup list to show several fields.
  • Have an ability to make an incremental search in lookup fields.
  • Can have frozen nonscrollable columns.
  • Allows to show DateTime picker for TDateField and TDateTimeField.
  • Allows to show bitmaps from TImageList depending on field value.
  • Allows to hide and track horizontal or vertical scrollbars.
  • Allows to hide columns.
  • Allows to show 3D frame for frozen, footer and data rows.
  • Allows to draw memo fields.
  • Can show multiline inplace editor.
  • Can have a proportional scrolling for DataSets independently of dataset’s sequencing.
  • Allows to show checkboxes automatically for Boolean fields. Allows to show checkboxes for other type of fields.
  • Has procedures to save and restore layout (visible columns, columns order, columns width, sortmarkers, row height) in/from registry or ini file.
  • Allows to show hint (ToolTips) for text that don't fit in the cell.
  • Allows to export data to Text, Csv, HTML, RTF, XLS and internal formats.
  • Allows to import data from Text and internal formats.
  • Can sort data in various datasets.
  • Can filter data in various datasets.

 

 
TDBVertGridEh component 

TDBVertGridEh Component is a Vertical Grid. The component is used to display and edit a single record DataSet in a vertical orientation. The data is displayed in two columns. The first column displays the names of the fields in the second field values of the current record. 

The component supports the following features:

  • Allows you to display Memo field of graphics and pictures Blob fields.
  • Allows you to wrap long lines and increase the height of each cell to display all the contents of the cell.
  • Allows the user to customize the mapping of cell data.
  • Has the event to dynamically change the font, color and other parameters of the cell, depending on the values of the fields of the current record.
  • Allows you to display special tips Tooltips for text that does not fit into the cell.
  • Allows you to have a dynamic line - created according to the dataset fields, and static - created and customized in advance DesignTime. It works the same as columns of Columns TDBGridEh.

 

 
TDBLookupComboboxEh component 

It provides all functionality of TDBLookupCombobox and adds several new features as follows:

  • Can have flat style.
  • Allows to assign values as to KeyValue property and as to display Text property.
  • Allows to hold KeyValue and Text that will not affect to each others values.

Drop down list can:

  • Show titles.
  • Have sizing grip.
  • Automatically set width as sum of DisplayWidth of the list fields (Width = -1).
  • Automatically drops when the user pressed the key.
  • Can have specified width.

Edit button can:

  • Show DropDown and Ellipsis or Bitmap image.

Has additional events: OnKeyValueChanged and OnButtonClick. 

 

 
TDBSumList component 

It is intended for calculating sums and amount of records in a TDataSet with dynamic changes. Component keeps a list of TDBSum objects, which contains types of group operations (goSum or goCount) and name of fields which values need some calculation (goCount name of field is unnecessary). 

 

 
TPrintDBGridEh component 

TPrintDBGridEh provides properties and routines for preview and print of TDBGridEh component with several features:

  • Ability to expand rows vertically until all text is printed.
  • Ability to scale grid to fit it to the page width.
  • Ability to print/preview title for grid.
  • Ability to print/preview page header and page footer where you can specify macros for current page, current date, current time and/or static text.
  • Automatically print/preview multi-selected area of TDBGridEh if it’s area is not empty.
  • Ability to print/preview rich text before and after grid.

 

 
TPreviewBox component 
 

TPreviewBox lets you to create a customizable runtime preview. 

 

 
TPrinterPreview object 
 

TPrinterPreview lets you to record printable data in buffer for following output them on screen and to printer. TPrinterPreview have all functions and properties as in TPrinter object. You can use TPrinterPreview object similarly to TPrinter except some details. In TPrinter Printer.Canvas.Handle and Printer.Handle is the same but in TPrinterPreview PrinterPreview.Canvas.Handle represents the metafile in that is recorded the data and PrinterPreview.Handle represents Printer.Handle. It means that you have to use PrinterPreview.Canvas.Handle for drawing operation (like DrawText, DrawTexteEx, e.t.c.) and use PrinterPreview.Handle for such functions as returning information about printer facilities (GetDeviceCaps, e.t.c.). Global function PrinterPreview returns default PrinterPreview object and shows data in the default preview form. 

 

 
TDBEditEh component 

Represents a single or multi-line edit control that can display and edit data of field in a dataset or can work as non data-aware edit control. 

 

 
TDBDateTimeEditEh component 

Represents a single-line date or time edit control that can display and edit data of TDateTime fields in dataset or can work as a non data-aware edit control. 

 

 
TDBComboBoxEh component 

Represents a single or multi-line edit control that combines an edit box with a scrollable list and can display and edit a field in a dataset or can work as non data-aware combo edit control. 

 

 
TDBNumberEditEh component 

Represents a single-line number edit control that can display and edit a numeric field in a dataset or can work as non data-aware edit control. 

 

 
TPropStorageEh, TIniPropStorageManEh, TRegPropStorageManEh components 

These components realize a technology of storing component properties to/from such storages as INI files, Registry etc. 

 

 
TMemTableEh component 

It is a dataset that holds all data in memory and can get data from TDataDriverEh and returns changed records back to the TDataDriverEh. 

 

 
TDataDriverEh component 

Delivers records from the server to the TMemTableEh. 

Delivers changed records from TMemTableEh back to the server. 

 

 
TDataSetDriverEh component 
 

It is a DataDriver that deliver records in TMemTableEh from other DataSet and deliver changed records from TMemTableEh back to the DataSet. 

 

 
TSQLDataDriverEh component 

It is a DataDriver that has properties for keeping five SQL expressions and parameters for querying data, removing, insertions, updating and refreshing records. TSQLDataDriverEh by itself can’t request data from server, but it can prepare parameters of the request and has a global event that programmer can write for transferring SQL expression to/from the server. 

 

 
TBDEDataDriverEh component 

It is a DataDriver that interacts with the DB server using BDE connection. 

 

 
TIBXDataDriverEh component 

It is a DataDriver that interacts with the DB server using IBX connection. 

 

 
TDBXDataDriverEh component 

It is a DataDriver that interacts with the DB server using DBX connection. 

 

 
TADODataDriverEh component 

It is a DataDriver that interacts with the DB server using ADO connection. 

 

 
TADOConnectionProviderEh component 
 

Provides the interface between the component TADODataDriver and TADOConnection in Design-Time and Run-Time. Contains built TADOConnection component. Specifies the type of server data for the correct operation of additional server operations, such as getting the value of the incremental table fields after inserting record, etc. 

 

 
TDBXConnectionProviderEh component 
 

Provides the interface between TDBXDataDriver and TSQLConnection in Design-Time and Run-Time. Contains embedded TSQLConnection component. Specifies the type of server data for the correct operation of additional server operations, such as getting the value of the incremental table fields after inserting record, etc. 

 

 
TIBXConnectionProviderEh component 
 

Provides the interface between the component TIBXDataDriver and TIBDatabase in Design-Time and Run-Time. Contains built TIBDatabase component. 

 

 
TBDEConnectionProviderEh component 
 

Provides the interface between the component TBDEDataDriver and TDatabase in Design-Time and Run-Time. Contains built TDatabase component. Specifies the type of server data for the correct operation of additional server operations, such as getting the value of the incremental table fields after inserting record, etc.

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