Copyright © 2004-2013 Curt Hill More Components Varying the input of Dev-C++ Windows Programs.

Copyright © 2004-2013 Curt Hill

More Components

Varying the input of Dev-C++ Windows Programs

Which Widgets?

• Menus• Memos• Check boxes• Radio buttons• List Boxes


Menus

• Two types:– Main menu – usually just below the

title bar– Popup – usually the result of a right

click

• What is it?– Just a specialized set of buttons

• Where: Menubars• Today we are only interested in the

main menuCopyright © 2004-2013 Curt Hill

Main Menu

• Click on wxMenuBar and drop on form

• It creates a component that does not look right until you run it

• Customize by clicking on the MenuItems entry– This brings the menu editor to front

• Then fill in the menu items


Initially


Dropped


Click Menu Items


After Enter


Notes• The menu editor will allow you to

create the top level menu and submenus– We will create File and Help for top level

• We click Add Item button for each entry– Fill in caption– Click apply

• The top level menu often has no event handler


After clicking add item


After clicking Create SubMenu


Basic Menu Design


Applying Events• A menu entry should act like a button• Clicking it should take us to an event• Clicking a top level menu may only

display a submenu– The event is done for us

• Now we apply the events– Click on Create– We get a save dialog– Then next screen


Add Event


Menu vs. Button

• When we create an event for a button it immediately takes us to the code panel

• When we create an event for a menu it creates the event but leaves us in design mode

• We do them all then look at code


One More Trick

• In the caption one ampersand may be inserted

• This causes the letter following it to be executed to be as a shortcut key

• Holding Alt and the letter is the same as clicking the mouse

• Each menu should only use a shortcut key once


Multi-Line EditBox

• A normal Edit has just one line• What if we want multiple lines?• Makes a nice area to log messages

to the user• Use the Memo in Common Controls• We do handle it a little differently

than an Edit


Memo in DevCPP

• The Strings property contains all the lines– Rarely is this assigned or referenced

• The AppendText method is usually used to add new material at bottom

• Escape sequences do work– Such as \n

• Use the cast to wxString and put to (<<) to display variables


String List Editor


• Click on the ellipsis (…) of the Strings property

• This starts the String List Editor• This sets initial values

Starting


After Setting


Closed


Check Boxes• Easiest way to enter a boolean

value• A check box may be checked or not

– Initialized in either form

• Design property is Checked– Use GetValue or IsChecked method

• Caption property is text next to checkbox

• Typical statement might be:if(CheckBox1->IsChecked()){// do something


Radio Buttons• The most visual way to choose one

out of 3 to 5• Similar to a check box but only one

may be selected• Clicking one clears all the rest• Checked is still the property• May be set at runtime by SetValue,

obtained by GetValue or IsChecked


Radio Buttons


Notes• Radio buttons are round and Check

boxes are square• Caption is the name next to

checkbox– Set to name

• Checked is the bool• Last one added will be checked if

none of the previous ones are checked– Will not see this in property inspector


Why Just 3 – 5?

• Not an absolute rule• Two radio buttons could be

replaced by one check box• More than five radio buttons gets

to be too bulky• Use a List box for that

– It may have very many items but only uses a small space


Determining Values• The Radio button also has GetValue

and IsChecked• Is that the best way to find what is

checked?• What would be needed was a series of

nested ifs:if(Radio1->IsChecked()){ … }else if(Radio2->IsChecked()){ … }else if(Radio3->IsChecked()){ … }else if(Radio4->IsChecked()){ … }

• Cannot use a switch for thisCopyright © 2004-2013 Curt Hill

Is there a better way?

• Use an enumeration• One for each radio button and one

for the unselected case• Use the On Click event handler for

the radio button to set the enumeration to this value

• When needing to decide on the radios, then use a switch on the enumeration


Finally

• There are many other controls• We will not need most of these for

this class• This should give sufficient control• Now is the time for the demo


Date post:	13-Dec-2015
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Copyright © 2004-2013 Curt Hill More Components Varying the input of Dev-C++ Windows Programs.

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