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This document covers the following topics:

• A Simple Example

• Selecting Rows in a TEXTGRID2

• Triggering Adapter Methods when Selecting a Row

• TEXTGRID2 Properties

• COLUMN Properties

• Dynamic Setting of Text Styles in TEXTGRID2

• Example: Displaying an ASCII Protocol

• Example: Using Images inside the TEXTGRID2 Control

• Specifying the Width of a TEXTGRID2 Control

• Change Index Management

• Flexible Columns with CSVCOLUMN

• CSVCOLUMN Properties

A Simple Example

The following example shows a TEXTGRID2 control:

There are two columns which hold data. There is one column at the very left which displays a selection icon - in addition to a yellow background for a selected line. Even and odd lines are displayed in slightly different colors. At the very right of each title column, there is a symbol which indicates the sorting status; if you double-click on this symbol, the column is sorted first in ascending direction and, when clicking again, in descending direction. Change the sequence of columns by dragging the title of a column and dropping it on another column's title. Depending from where you drop, the column is either moved left or right.

The asterisk in the upper left corner of the grid is used to select/deselect all lines in the grid. The behavior depends on the setting of the singleselect property which determines whether multiple lines can be selected in the grid (default) or whether only one line can be selected:

• Multiple Line Selection Mode
  When you choose the asterisk for the first time, all lines are selected. When you choose the asterisk a second time, all lines are deselected.

• Single Line Selection Mode
  When you choose the asterisk (no matter how often), an existing selected line is deselected.

The XML layout definition is:

<rowarea name="Textgrid">
    <itr takefullwidth="true" fixlayout="true">
        <textgrid2 griddataprop="lines" width="100%" height="200" selectprop="selected"
                   hscroll="true">
            <column name="First Name" property="firstName" width="50%">
            </column>
            <column name="Last Name" property="lastName" width="50%">
            </column>
        </textgrid2>
    </itr>
    <vdist height="5">
    </vdist>
</rowarea>

The TEXTGRID2 definition is bound to a grid data property lines. This is a special collection that mirrors the server data. Technically, it is treated in the same way as a normal collection. It supports the Collection and List interface.

Inside the TEXTGRID2 control definition there are two columns. These columns are bound to the properties firstName and lastName.

This is the Java adapter source:

import com.softwareag.cis.server.Adapter;
import com.softwareag.cis.server.util.SelectableLine;
import com.softwareag.cis.server.util.TEXTGRIDCollection;

// This class is a generated one.

public class TextGridAdapter
    extends Adapter
{
    // class >LinesItem<
    public class LinesItem
    extends SelectableLine
    {
        // property >firstName<
        String m_firstName;
        public String getFirstName() { return m_firstName; }

        // property >lastName<
        String m_lastName;
        public String getLastName() { return m_lastName; }

        // property >selected<
        boolean m_selected;
        public boolean getSelected() { return m_selected; }
        public void setSelected(boolean value) { m_selected = value; }
    }

    // property >lines<
    TEXTGRIDCollection m_lines = new TEXTGRIDCollection();
    public TEXTGRIDCollection getLines() { return m_lines; }

    /** initialisation - called when creating this instance*/
    public void init()
    {
        for (int i=0; i< 50; i++)
        {
            LinesItem l = new LinesItem();
            l.m_firstName = "First " + i;
            l.m_lastName = "Last " + i;
            m_lines.add(l);
        }
    }
}

The adapter class provides a property lines. This property returns an instance of the class TEXTGRIDCollection which itself is a special collection and comes with the Application Designer runtime. The instance is filled in the init() method of the adapter - just as a normal collection. But it automatically brings in all the functions for sorting and - if desired - server-side scrolling (see the TEXTGRIDSSS2 description).

The collection is filled with objects of the inner class Line. Each object supports a property firstName, lastName and selected. (The class Line is an inner class in the example - but of course it could also be a normal class). Make sure to make the class publicly accessible, because the Application Designer runtime requires public access to the corresponding properties.

The whole TEXTGRID2 definition is bound by the griddataprop property to the lines collection - and each COLUMN definition is bound to a property of class Line, i.e. the class representing elements of the collection.

Selecting Rows in a TEXTGRID2

Maybe you wonder why there is a selected property in the class Line of the previous example.

This property is required for indicating which lines are currently selected and which are not. Each line which is displayed in the TEXTGRID2 control is represented at the server side by an object of the class Line. Therefore, the selection status of the grid (which lines are selected and which lines are not) is mirrored by the corresponding selected property of each line.

The code below shows an extension of the previous example. It demonstrates how to build a method for taking the line selection into consideration.

Below the TEXTGRID2 definition, there is a button that triggers a method for removing the selected lines.

The XML layout definition is improved in the following way:

<rowarea name="Textgrid">
    <itr takefullwidth="true" fixlayout="true">
        <textgrid2 griddataprop="lines" width="100%" height="200" selectprop="selected"
                   hscroll="true">
            <column name="First Name" property="firstName" width="50%">
            </column>
            <column name="Last Name" property="lastName" width="50%">
            </column>
        </textgrid2>
    </itr>
    <vdist height="5">
    </vdist>
    <itr>
        <button name="Remove Selected Items" method="onRemoveSelectedItems">
        </button>
    </itr>
    <vdist>
    </vdist>
</rowarea>

Note that inside the TEXTGRID2 definition, there is a property selectprop that points to the name of the item property used for storing the selection information accordingly.

The method onRemoveSelectedItems was added into the adapter code of the previous example:

public void onRemoveSelectedItems()
{
    for (int i=m_lines.size()-1; i>=0; i--)
    {
    LinesItem l = (LinesItem)m_lines.get(i);
    if (l.getSelected() == true)
    m_lines.remove(i);
}

The collection is iterated from its last element to its first. All elements which hold a selected property with value "true" are removed.

Note:
In this example, you are able to select multiple rows inside the grid. If you want to allow selecting only one item, use the property singleselect inside the TEXTGRID2 definition.

Triggering Adapter Methods when Selecting a Row

In the previous section, you saw how to manage selections inside a TEXTGRID2 control. Sometimes, you want to trigger a certain function when selecting a row - maybe you want to react directly to the selected item.

To do so, you can use some additional properties inside the TEXTGRID2 definition:

• The onclickmethod property is used to point to a method of your adapter class which is called when a click event occurs.

• The ondblclickmethod property is used when the user double-clicks a grid row.

You can use "direct triggering of method" together with single line selection mode or with multiple line selection mode. In case of using it with multiple line selection, you have to find out which was the "last selected index", i.e. the line index of the clicked/double-clicked line.

There is a property lastselectedprop inside the TEXTGRID2 definition. Using this definition, you can bind the value to an integer property of your adapter class. The index value which is selected is passed into this property.

TEXTGRID2 Properties

COLUMN Properties

The COLUMN tag is the typical tag that is placed inside a TEXTGRID2 definition. The COLUMN definition defines a column with its binding to a property of the collection elements.

Tip:
If you set the property headernowrap="false", you usually have to increase the height of the header in the style sheet of your layout page. You can do this in the Style Sheet Editor: Go to the Style Details tab, expand the tree for TEXTGRID and then adjust the height value for TEXTGRIDCellHeaderUnsorted.

Dynamic Setting of Text Styles in TEXTGRID2

The example from the previous sections will now be enhanced in order to demonstrate how to control the style of cells inside a TEXTGRID2 control dynamically:

Some of the cells in the TEXTGRID2 control are rendered with a different style than the normal one. Each COLUMN definition has the property textstyleprop:

<rowarea name="Textgrid">
    <itr takefullwidth="true" fixlayout="true">
        <textgrid2 griddataprop="lines" width="100%" height="200" selectprop="selected"
                   hscroll="true">
            <column name="First Name" property="firstName" width="50%"
                    textstyleprop="firstNameStyle">
            </column>
            <column name="Last Name" property="lastname" width="50%"
                    textstyleprop="lastNameStyle">
            </column>
        </textgrid2>
    </itr>
    <vdist height="5">
    </vdist>
    <itr>
        <button name="Remove Selected Items" method="onRemoveSelectedItems">
        </button>
    </itr>
</rowarea>

The referenced property inside the COLUMN definition is on the same level as the normal property that is responsible for the content of the columns and which is referenced by the normal property property. Have a look at the Java source:

// This class is a generated one.

import com.softwareag.cis.server.Adapter;
import com.softwareag.cis.server.util.SelectableLine;
import com.softwareag.cis.server.util.TEXTGRIDCollection;

// This class is a generated one.

public class TextGridAdapter
    extends Adapter
{
    // class >LinesItem<
    public class LinesItem
    extends SelectableLine
    {
        // property >firstName<
        String m_firstName;
        public String getFirstName() { return m_firstName; }

        // property >lastName<
        String m_lastName;
        public String getLastName() { return m_lastName; }

        // property >selected<
        boolean m_selected;
        public boolean getSelected() { return m_selected; }
        public void setSelected(boolean value) { m_selected = value; }

        // property >firstNameStyle<
        String m_firstNameStyle;
        public String getFirstNameStyle() { return m_firstNameStyle; }
        public void setFirstNameStyle(String value) { m_firstNameStyle = value; }

        // property >lastNameStyle<
        String m_lastNameStyle;
        public String getLastNameStyle() { return m_lastNameStyle; }
        public void setLastNameStyle(String value) { m_lastNameStyle = value; }
    }

    // property >lines<
    TEXTGRIDCollection m_lines = new TEXTGRIDCollection();
    public TEXTGRIDCollection getLines() { return m_lines; }

    ...

    /** initialisation - called when creating this instance*/
    public void init()
    {
        for (int i=0; i< 50; i++)
        {
        LinesItem l = new LinesItem();
        l.m_firstName = "First " + i;
        l.m_lastName = "Last " + i;
        if (i%3 == 2)
            l.setFirstNameStyle("color: #FF0000;");
        if (i%4 == 3)
            l.setLastNameStyle("color: #0000FF; background-color: #C0C0C0");
        m_lines.add(l);
        }
    }
}

The properties lastNameStyle and firstNameStyle are available on item level. They are filled in the init() method.

Example: Displaying an ASCII Protocol

The following example shows the output of an ASCII protocol. The example demonstrates the usage of the COLUMN properties textstyleprop and convertspaces.

The XML layout definition looks as follows:

<page model="Ascii_Protocol_Adapter">
    <titlebar name="ASCII Protocol">
    </titlebar>
    <header withdistance="false">
        <button name="Save">
        </button>
    </header>
    <pagebody>
        <rowarea name="Protocol Output">
            <itr takefullwidth="false" height="350" fixlayout="true">
                <textgrid2 griddataprop="items" width="100%" height="100%" hscroll="true"
                           vscroll="true" backgroundstyle="background-color:#000000">
                    <column name="Protocol" property="protocolText" width="1000"
                            textstyleprop="protocolStyle" convertspaces="true">
                    </column>
                </textgrid2>
            </itr>
        </rowarea>
    </pagebody>
    <statusbar withdistance="false">
    </statusbar>
</page>

The following is defined in the above layout definition:

• Inside the TEXTGRID2 definition, a black background is defined (backgroundstyle property).

• Inside the COLUMN definition, a style property is referenced (textstyleprop property).

• Inside the COLUMN definition, the property convertspaces is set to "true".

The Java source looks as follows:

import com.softwareag.cis.server.Adapter;
import com.softwareag.cis.server.util.TEXTGRIDCollection;

// This class is a generated one.

public class Ascii_Protocol_Adapter
    extends Adapter
{
    // ------------------------------------------------------------------------
    // inner classes
    // ------------------------------------------------------------------------

    // class >ItemsItem<
    public class Item
    {
        // property >protocolStyle<
        String m_centralStyle = "font-family: courier; color: #00FFFF; background-color: #000000;";
        String m_protocolStyle;
        public String getProtocolStyle() { return m_centralStyle; }

        // property >protocolText<
        String m_protocolText;
        public String getProtocolText() { return m_protocolText; }
        public void setProtocolText(String value) { m_protocolText = value; }
    }
    // ------------------------------------------------------------------------
    // property access
    // ------------------------------------------------------------------------

    // property >items<
    TEXTGRIDCollection m_items = new TEXTGRIDCollection();
    public TEXTGRIDCollection getItems() { return m_items; }

    // ------------------------------------------------------------------------
    // standard adapter methods
    // ------------------------------------------------------------------------

    /** initialisation - called when creating this instance*/
    public void init()
    {
        Item item;
        item = new Item(); item.setProtocolText("BATCH RUN (01.04.2002)"); m_items.add(item);
        item = new Item(); item.setProtocolText("======================"); m_items.add(item);
        item = new Item(); item.setProtocolText(""); m_items.add(item);
        item = new Item(); item.setProtocolText("Time consuumed : 48.000 ms");
        m_items.add(item);
        item = new Item(); item.setProtocolText("Waiting time : 3.452 ms");
        m_items.add(item);
        item = new Item(); item.setProtocolText("Database time : 32.203 ms");
        m_items.add(item);
        item = new Item(); item.setProtocolText("App Server time : 10.485 ms");
        m_items.add(item);
        item = new Item(); item.setProtocolText(""); m_items.add(item);
        item = new Item(); item.setProtocolText("Return Code : 0 (OK)"); m_items.add(item);
    }
}

Example: Using Images inside the TEXTGRID2 Control

In the following text grid, graphical information and text information are mixed:

The layout definition looks as follows:

<rowarea name="Textgrid with contained Icons">
    <itr takefullwidth="tue">
        <textgrid2 griddataprop="lines" width="100%" height="200">
            <column name="Icon" width="53" imageprop="iconURL">
            </column>
            <column name="Text" property="text" width="100%">
            </column>
        </textgrid2>
    </itr>
</rowarea>

In the definition of the left column, the property imageprop is used to reference to a property that provides the URL string of the image to be displayed. The definition of the right column contains the property property that points to a property providing text information.

The adapter class looks as follows:

// This class is a generated one.

import com.softwareag.cis.server.Adapter;
import com.softwareag.cis.server.util.TEXTGRIDCollection;

public class Textgrid_02_Adapter
    extends Adapter
    {
    // ------------------------------------------------------------------------
    // inner classes
    // ------------------------------------------------------------------------
    // class >LinesItem<
    public class LinesItem
    {
        // property >iconURL<
        String m_iconURL;
        public String getIconURL() { return m_iconURL; }
        public void setIconURL(String value) { m_iconURL = value; }

        // property >text<
        String m_text;
        public String getText() { return m_text; }
        public void setText(String value) { m_text = value; }
    }
    // ------------------------------------------------------------------------
    // property access
    // ------------------------------------------------------------------------
    // property >lines<
    TEXTGRIDCollection m_lines = new TEXTGRIDCollection();
    public TEXTGRIDCollection getLines() { return m_lines; }

    // ------------------------------------------------------------------------
    // standard adapter methods
    // ------------------------------------------------------------------------
   /** initialisation - called when creating this instance*/
    public void init()
    {
        for (int i=0; i<10; i++)
        {
        LinesItem l = new LinesItem();
        l.setIconURL("images/touch_"+i+".gif");
        l.setText("This is icon number " + i);
        m_lines.add(l);
        }
    }

You can also mix text and image by specifying the property and the imageprop property. In this case, the image will be drawn on the left and the text will be placed to the right of the image.

Specifying the Width of a TEXTGRID2 Control

The sizing of text grids was improved with a previous release: now you can simply set a width of e.g. "100%" if the text grid should cover the complete width that is available.

Pay attention to the following:

• If you do not specify a width inside the TEXTGRID2 definition, the width of the grid will be as wide as defined by its content. Of course, it does not make sense to define a percentage value inside the COLUMN definitions - there is nothing to refer to.

• If you specify a width in the TEXTGRID2 and you already know that the size of the columns does not fit into the given width, you must set the flag HSCROLL to "true". Otherwise, there will be no scrolling at all and the grid will be rendered as wide as required by its content.

• If you specify a percentage value as a width for the TEXTGRID2 control, you must place the grid into an ITR definition that itself has also a WIDTH definition (typically of "100%"). In addition, you must set the flag FIXLAYOUT to "true" on ITR level. Otherwise the grid will follow the width of its contained columns.

Change Index Management

In order to improve performance on the client side, there is a so-called change index management: a text grid binds to an array of data records. Every time when the browser client receives updated data from the server, it finds out whether a text grid has to be updated or not. Updating a text grid is a quite expensive operation for the client - consequently, it is done only if really necessary.

For this reason, each TEXTGRIDCollection object implicitly administers a change index. A change index is a property of type long. The value of the property always changes if something inside the collection changes. The client reads this property and only refreshes the text grid if the property has changed.

Normally, the property is managed internally - without you being involved. If a TEXTGRIDCollection is manipulated via its methods (e.g. add or clear), then the property is automatically updated - and consequently, the client refreshes. But: if a change of data happens inside one item of a TEXTGRIDCollection, then the call does not go through the TEXTGRIDCollection API. Consequently, you have to explicitly trigger the update by your program. Inside the TEXTGRIDCollection, there is a method itemChanged() which indicates that due to the change of data within one item the grid has to be updated.

The following example shows how to control the change index. In this example, a text grid is built and manipulated by three buttons:

With the first button, new items are added to the grid. With the second button, all items receive new content. With the third button, the change index will be updated.

The XML code is:

<rowarea name="Textgrid with Change Index Management">
    <itr>
        <textgrid2 griddataprop="lines_02" width="100%" height="200">
            <column name="Text" property="text" width="100%">
            </column>
        </textgrid2>
    </itr>
    <itr>
        <button name="Add Data Line" method="onAddDataLine">
        </button>
        <button name="Update Data Lines" method="onUpdateDataLines">
        </button>
        <button name="Update Change Index" method="onUpdateChangeIndex">
        </button>
    </itr>
</rowarea>

The Java adapter source is shown below. Pay attention to the constructor of the m_lines member (which passes "true" as a parameter) and to the method m_lines.itemChanged() that is called in order to update the change index implicitly.

// This class is a generated one.

import java.util.Date;
import java.util.Iterator;

import com.softwareag.cis.server.Adapter;
import com.softwareag.cis.server.util.TEXTGRIDCollection;

public class Textgrid_02_Adapter
    extends Adapter
{
    // ------------------------------------------------------------------------
    // inner classes
    // ------------------------------------------------------------------------
    // class >Lines_02Item<
    public class Lines_02Item
    {
        // property >text<
        String m_text;
        public String getText() { return m_text; }
        public void setText(String value) { m_text = value; }
    }
    // ------------------------------------------------------------------------
    // property access
    // ------------------------------------------------------------------------

    // property >lines_02<
    TEXTGRIDCollection m_lines_02 = new TEXTGRIDCollection();
    public TEXTGRIDCollection getLines_02() { return m_lines_02; }

    // ------------------------------------------------------------------------
    // public adapter methods
    // ------------------------------------------------------------------------
    /** */
    public void onAddDataLine()
    {
        Lines_02Item l = new Lines_02Item();
        l.setText((new Date()).toString());
        m_lines_02.add(l);
    }

    /** */
    public void onUpdateChangeIndex()
    {
        m_lines_02.itemChanged();
    }

    /** */
    public void onUpdateDataLines()
    {
        Iterator iter = m_lines_02.iterator();
        while (iter.hasNext())
        {
        Lines_02Item l = (Lines_02Item)iter.next();
        l.setText((new Date()).toString());
        }
    }
}

The behavior of the text grid control is as follows:

• If a new line is added (method onAddDataLine()), the change index will be updated internally - you do not have to explicitly tell the text grid management that something has changed.

• If the lines are updated (method onUpdateDataLines()), changes will not be reflected in the grid - until you explicitly trigger the method onUpdateChanngeIndex().

Consequence: every time you change the inner content of the grid data, you have to update the change index by yourself.

Flexible Columns with CSVCOLUMN

There are situations in which the number and the format of the columns of a text grid cannot be defined in a fixed way inside the layout definition. The column type CSVCOLUMN allows you to dynamically define columns of a grid by your adapter program.

Have a look at the following example:

The control looks like a normal text grid. When looking inside the XML layout definition, you find out that instead of three fixed columns there is one dynamic column definition:

<rowarea name="Rowarea">
    <itr>
        <textgrid2 griddataprop="lines" width="100%" height="150" selectprop="selected"
                   singleselect="true" hscroll="true">
            <csvcolumn titlesprop="gridTitles" valuesprop="values" widthsprop="gridWidths"
                       alignsprop="gridAligns" backgroundsprop="backgrounds">
            </csvcolumn>
        </textgrid2>
    </itr>
</rowarea>

Inside the CSVCOLUMN definition, there is a binding to various properties that are provided for by the corresponding adapter:

// This class is a generated one.

import com.softwareag.cis.file.CSVManager;
import com.softwareag.cis.server.Adapter;
import com.softwareag.cis.server.util.TEXTGRIDCollection;


public class textgrid_03_Adapter
    extends Adapter
{
    // ------------------------------------------------------------------------
    // inner classes
    // ------------------------------------------------------------------------
   // class >LinesItem<
    public class LinesItem
    {
        public LinesItem (String values, String backgrounds)
        {
            m_values = values;
            m_backgrounds = backgrounds;
        }

        // property >backgrounds<
        String m_backgrounds;
        public String getBackgrounds() { return m_backgrounds; }
        public void setBackgrounds(String value) { m_backgrounds = value; }

        // property >selected<
        boolean m_selected;
        public boolean getSelected() { return m_selected; }
        public void setSelected(boolean value) { m_selected = value; }

        // property >values<
        String m_values;
        public String getValues() { return m_values; }
        public void setValues(String value) { m_values = value; }
    }
    // ------------------------------------------------------------------------
    // property access
    // ------------------------------------------------------------------------
    String m_gridAligns = CSVManager.encodeString(new String[] {
            "left",
            "left",
            "right"
            });
    public String getGridAligns() { return m_gridAligns; }

    String m_gridTitles = CSVManager.encodeString(new String[] {
            "First",
            "Second",
            "Third"
            });
    public String getGridTitles() { return m_gridTitles; }

    String m_gridWidths = CSVManager.encodeString(new String[] {
            "200",
            "200",
            "200"
            });
     public String getGridWidths() { return m_gridWidths; }

    // property >lines<
    TEXTGRIDCollection m_lines = new TEXTGRIDCollection();
    public TEXTGRIDCollection getLines() { return m_lines; }

    // ------------------------------------------------------------------------
    // public adapter methods
    // ------------------------------------------------------------------------
    /** initialisation - called when creating this instance*/
    public void init()
    {
        m_lines.add(new LinesItem("100;100;100","#FF0000;#00FF00;#0000FF"));
        m_lines.add(new LinesItem("200;200;200","#00FF00;#FF0000;#0000FF"));
        m_lines.add(new LinesItem("300;400;500","#FF0000;#FF0080;#FF00FF"));
    }
}

The information for creating dynamic columns is passed as comma separated values. Comma separated values are either created directly as a string or by calling a static method of the class com.softwareag.cis.file.CSVManager.

Note:
When using the CSVManager methods for creating comma separated value strings, this always pays attention to what happens if strings already include one or more semicolons.

Example: the CSVManager will encode the strings "A", "B1;B2" and "C" to "A;B1\;B2;C". On the client side, the "\;" is decoded back to ";".

Compare the layout definition with the code example in order to find out the exact binding technique between the control and the adapter properties.

CSVCOLUMN Properties

Tip:
If you set the property headernowrap="false", you usually have to increase the height of the header in the style sheet of your layout page. You can do this in the Style Sheet Editor: Go to the Style Details tab, expand the tree for TEXTGRID and then adjust the height value for TEXTGRIDCellHeaderUnsorted.

The properties of the CSVCOLUMN control are:

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