my head stuck in the computer: GtkAda Button Clicks and Containers

GtkAda Button Clicks and Containers

Since I reported that I was beginning to understand GtkAda I've found that I had more to learn.

I've gone further to display a group of buttons at different positions within the display window and to field button clicks to hide and show a button as well as to display text on the button in different fonts, sizes, colors and font styles.

The examples to hide a button all seemed to be to hide the button that was clicked. So it took a little bit to figure out how to reference a different button instead. (How can you click on a hidden button to redisplay it?) And even more time to find out how to select the font, font size, etc. The examples just didn't seem to compile. Maybe I've developed old age disease but it took me a while to come up with what would compile. (The GtkAda code makes use of some esoteric Ada constructs.) But when I got the solution it became easy.

I then wanted to put the button widgets into a parent container widget since this is standard practice in aircraft ARINC 661 standard. Thus being able to hide the parent widget to hide all its child widgets. However, looking at the GtkAda types of containers (vertical boxes, horizontal boxes, grids) they all wanted to place the widget themselves whereas A661 has widgets placed within their container by their x, y position from the container boundary.

So I wrote my own container widget generic package so as to be able to hide or show the container and have its widgets hidden or visible. After my attempts to use GtkAda this was a snap. Although it doesn't yet place the widgets relative to the containers position or even specify a position for the container. So the widgets are still placed relative to the window.

This resulted in the following set of views.

First I have a view with only one button (the one not in the container) visible. To do this I had to first do a Show All on the window and all its contents and then do a hide of the container. This doesn't flash the buttons since GtkAda doesn't act on the Show All until the signal handling loop is activated. View 1 shows the result.

Next I clicked on the Sixth button which is tied to an event handler that toggles the display of the container from hidden to displayed or vice versa. See View 2 where buttons First thru Fifth are also displayed in their different sizes, fonts and positions.

Next I clicked the First button which is tied to an event handler that toggles the display of the second button. The results are shown in View 3 where the Second button is no longer displayed.

To illustrate how the Second button will remain hidden when the container is hidden and then redisplayed, the Sixth button was again clicked resulting in View 5. Then the First button was clicked to redisplay the Second button as in the final view.

For those interested, the applicable code follows.

with Gtk;

with Gtk.Box;

with Gtk.Button;

with Gtk.Button_Box;

with Gtk.Enums;

with Gtk.Handlers;

with Gtk.Fixed;

with Gtk.Font_Button;

with Gtk.Frame;

with Gtk.Hbutton_Box;

with Gtk.Widget;

with Gtk.Window;

package body Layer1 is

Win

-- Main Window of layer 1

: Gtk.Window.Gtk_Window;

Frame : Gtk.Frame.Gtk_Frame;

-- where Gtk_Frame is access all Gtk_Frame_Record'Class;

Fix : Gtk.Fixed.Gtk_Fixed;

FButtonFirst : Gtk.Button.Gtk_Button;

FButtonSecond : Gtk.Button.Gtk_Button;

FButtonThird : Gtk.Button.Gtk_Button;

FButtonFourth : Gtk.Button.Gtk_Button;

FButtonFifth : Gtk.Button.Gtk_Button;

FButtonSixth : Gtk.Button.Gtk_Button;

function Delete_Event

-- Treat Delete button of upper right of Window

( Object : access Gtk.Widget.Gtk_Widget_Record'Class

) return Boolean;

-- Callback when the main window is killed

package Container

--| Instantiate Container for buttons First thru Fifth

is new Gtk_Container( Size => 10 );

-----------------------------------------------------------------------------

package Events is

-- Treat widget events

procedure Treat_First_Click_Event

( Object : access Gtk.Widget.Gtk_Widget_Record'Class );

-- Callback when the FButtonFirst button is clicked

procedure Treat_Second_Click_Event

( Object : access Gtk.Widget.Gtk_Widget_Record'Class );

-- Callback when the FButtonSecond button is clicked

procedure Treat_Third_Click_Event

( Object : access Gtk.Widget.Gtk_Widget_Record'Class );

-- Callback when the FButtonThird button is clicked

procedure Treat_Fourth_Click_Event

( Object : access Gtk.Widget.Gtk_Widget_Record'Class );

-- Callback when the FButtonFourth button is clicked

procedure Treat_Fifth_Click_Event

( Object : access Gtk.Widget.Gtk_Widget_Record'Class );

-- Callback when the FButtonFifth button is clicked

procedure Treat_Sixth_Click_Event

( Object : access Gtk.Widget.Gtk_Widget_Record'Class );

-- Callback when the FButtonSixth button is clicked

end Events;

-----------------------------------------------------------------------------

-- Window events

function Delete_Event

( Object : access Gtk.Widget.Gtk_Widget_Record'Class) return Boolean

pragma Unreferenced (Object);

begin

return True; -- to avoid killing the Layer1 window when

–- the X button is clicked

end Delete_Event;

package body Events is separate;

end Layer1;

with Glib;

with Gtk.Font_Chooser;

with Gtk.Font_Chooser_Widget;

with Gtk.Handlers;

with Gtk.Label;

with Pango.Font;

separate( A661.Layer1 )

procedure Initialize is

begin -- Initialize

-- Install the configuration.

Configuration.Initialize;

-- Build the main window.

Configuration.Build_Window( Window => 100 );

-- Initializes GtkAda

Gtk.Main.Init;

-- Create the basic window

Gtk.Window.Gtk_New

( Window => Win,

The_Type => Gtk.Enums.Window_Toplevel );

-- Position the window in the center of the screen

Gtk.Window.Set_Position( Win, Gtk.Enums.Win_Pos_Center );

-- Set the window size

Gtk.Window.Set_Default_Size( Win, 800, 500 );

-- Set a window title

Gtk.Window.Set_Title

( Window => Win,

Title => "Layer 1" );

-- Connect the Delete_Event procedure to the Window Close button

Return_Window_CB.Connect

( Win,

"delete_event", -- Close button event

Return_Window_CB.To_Marshaller( Delete_Event'Access) );

--------------------------

-- create a frame

Gtk.Frame.Gtk_New( Frame );

Frame.Set_Shadow_Type( Gtk.Enums.Shadow_In );

Win.Add( Frame );

Gtk.Fixed.Gtk_New( Fix );

Gtk.Frame.Add( Frame, Fix );

Gtk.Button.Gtk_New( FButtonFirst, "First" );

Gtk.Fixed.Put( Fix, FButtonFirst, 10, 10 );

Gtk.Label.Set_Markup

( Gtk.Label.GTk_Label(Gtk.Button.Get_Child(FButtonFirst)),

"First");

Window_CB.Object_Connect

( FButtonFirst, "clicked",

Window_CB.To_Marshaller(Events.Treat_First_Click_Event'Access), Win );

declare

Added : Boolean;

ButtonRec : Container.Widget_Record;

begin

ButtonRec.Widget := FButtonFirst;

ButtonRec.Id := 1001;

ButtonRec.Visible := True;

Added := Container.Add( Widget => ButtonRec );

end;

Gtk.Button.Gtk_New( FButtonSecond, "Second" );

Gtk.Fixed.Put( Fix, FButtonSecond, 20, 80 );

Gtk.Label.Set_Markup

( Gtk.Label.GTk_Label(Gtk.Button.Get_Child(FButtonSecond)),

"Second");

Window_CB.Object_Connect

( FButtonSecond, "clicked",

Window_CB.To_Marshaller(Events.Treat_Second_Click_Event'Access), Win );

declare

Added : Boolean;

ButtonRec : Container.Widget_Record;

begin

ButtonRec.Widget := FButtonSecond;

ButtonRec.Id := 1002;

ButtonRec.Visible := True;

Added := Container.Add( Widget => ButtonRec );

end;

Gtk.Button.Gtk_New( FButtonThird, "Third" );

Gtk.Fixed.Put( Fix, FButtonThird, 80, 30 );

Gtk.Label.Set_Markup

( Gtk.Label.Gtk_Label(Gtk.Button.Get_Child(FButtonThird)),

"Third");

Window_CB.Object_Connect

( FButtonThird, "clicked",

Window_CB.To_Marshaller(Events.Treat_Third_Click_Event'Access), Win );

declare

Added : Boolean;

ButtonRec : Container.Widget_Record; --My_Button_Record;

begin

ButtonRec.Widget := FButtonThird;

ButtonRec.Id := 1003;

ButtonRec.Visible := True;

Added := Container.Add( Widget => ButtonRec );

end;

Gtk.Button.Gtk_New( FButtonFourth, "Fourth" );

Gtk.Button.Set_Size_Request( FButtonFourth, 40, 50 );

Gtk.Fixed.Put( Fix, FButtonFourth, 100, 150 );

Gtk.Label.Set_Markup

( Gtk.Label.GTk_Label(Gtk.Button.Get_Child(FButtonFourth)),

"Fourth");

Window_CB.Object_Connect

( FButtonFourth, "clicked",

Window_CB.To_Marshaller(Events.Treat_Fourth_Click_Event'Access), Win );

declare

Added : Boolean;

ButtonRec : Container.Widget_Record;

begin

ButtonRec.Widget := FButtonFourth;

ButtonRec.Id := 1004;

ButtonRec.Visible := True;

Added := Container.Add( Widget => ButtonRec );

end;

Gtk.Button.Gtk_New( FButtonFifth, "Fifth" );

Gtk.Button.Set_Size_Request( FButtonFifth, 150, 50 );

Gtk.Fixed.Put( Fix, FButtonFifth, 10, 280 );

Gtk.Label.Set_Markup

( Gtk.Label.GTk_Label(Gtk.Button.Get_Child(FButtonFifth)),

"Fifth");

Window_CB.Object_Connect

( FButtonFifth, "clicked",

Window_CB.To_Marshaller(Events.Treat_Fifth_Click_Event'Access), Win );

declare

Added : Boolean;

ButtonRec : Container.Widget_Record; --My_Button_Record;

begin

ButtonRec.Widget := FButtonFifth;

ButtonRec.Id := 1005;

ButtonRec.Visible := True;

Added := Container.Add( Widget => ButtonRec );

end;

Gtk.Button.Gtk_New( FButtonSixth, "Sixth" );

Gtk.Button.Set_Size_Request( FButtonSixth, 150, 50 );

Gtk.Fixed.Put( Fix, FButtonSixth, 200, 280 );

Gtk.Label.Set_Markup

( Gtk.Label.GTk_Label(Gtk.Button.Get_Child(FButtonSixth)),

"Sixth");

Window_CB.Object_Connect

( FButtonSixth, "clicked",

Window_CB.To_Marshaller(Events.Treat_Sixth_Click_Event'Access), Win );

-- Note: Not part of the Container since it must stay visible for alternate

-- clicks to show the container again.

–-> code from Parse that displays the window when App2

–- sends the command to do so

-- Show the window.

Gtk.Window.Show_All( Win );

-- Hide the container and its widgets to start

Container.Hide;

-- Activate the signal handling loop to allow use of click events

Gtk.Main.Main;

end Initialize;

package body Events is

-----------------------------------------------------------------------------

-- Button click event handlers

procedure Treat_First_Click_Event

( Object : access Gtk.Widget.Gtk_Widget_Record'Class

) is

-- Callback when the FButtonFirst button is clicked

pragma Unreferenced( Object );

begin -- Treat_First_Click_Event

if Container.Is_Visible( Widget => FButtonSecond ) then

Container.Hide( Widget => FButtonSecond );

else

Container.Show( Widget => FButtonSecond );

end if;

end Treat_First_Click_Event;

procedure Treat_Sixth_Click_Event

( Object : access Gtk.Widget.Gtk_Widget_Record'Class

) is

-- Callback when the FButtonSixth button is clicked

pragma Unreferenced( Object );

begin -- Treat_Sixth_Click_Event

Console.Write( "Button Sixth clicked" );

if Container.Is_Visible then

Container.Hide;

else -- supposed to be visible, refresh it

Container.Show;

end if;

end Treat_Sixth_Click_Event;

end Events;

with Gtk.Button; -- change to Gtk.Widget

generic

-- Overview:

-- Generic package to group widgets as their parent.

-- Widgets can be added to the container and then the widgets

-- can be hidden or made visible as a group by invoking the

-- Hide or Show procedure of the container.

-- The container is different from a GtkAda container package

-- since there is no restriction as to how the widgets can be

-- placed in relation to each other.

-- Notes:

-- Parameter to supply when instantiate an instance of a topic.

Size

-- Maximum number of widgets allowed to be added to the container.

: Integer;

package Gtk_Container is

-- Treat a group/array of widgets as being in a container as far as hiding

-- or making visible.

type Widget_Id_Type

--| Define 16-bit widget identifier

is new Integer range 0..32767;

for Widget_Id_Type'size use 16; -- bits

-- Note: Needs its own declaration since circularity results if use A661.Types

type Widget_Record is new Gtk.Button.Gtk_Button_Record with record

Widget : Gtk.Button.Gtk_Button;

--<<< will need to generalize to a Gtk Widget >>>

Id : Widget_Id_Type;

Visible : Boolean;

end record;

type Widget is access all Widget_Record'Class;

function Add

( Widget : in Widget_Record

--will want a general type (from Configuration) rather than just for buttons

) return Boolean;

-- Add a widget to the container.

-- Return True if the Add was successful

procedure Hide;

-- Hide all the widgets of the container

procedure Hide

( Widget : in Gtk.Button.Gtk_Button

-- Widget being hidden

);

-- Hide the named widget of the container

procedure Show;

-- Show all the widgets of the container

procedure Show

( Widget : in Gtk.Button.Gtk_Button

-- Widget being shown

);

-- Show the named widget of the container

function Is_Visible

return Boolean;

-- Returns whether the container is set to be visible

function Is_Visible

( Widget : in Gtk.Button.Gtk_Button

-- Widget being checked

) return Boolean;

-- Returns whether the widget is set to be visible

end Gtk_Container;

with Gtk.Widget;

package body Gtk_Container is

type Widget_Count_Type

is new Integer range 0..Size; --Max;

type Widget_Array_Type

is array (1..Widget_Count_Type'last) of Widget_Record;

type Widget_List_Type

is record

Count : Widget_Count_Type;

Visible : Boolean;

List : Widget_Array_Type;

end record;

type Container_Type

is record

Visible : Boolean;

-- True if container has been requested to be visible

Data : Widget_List_Type;

-- Data concerning the widgets of the container

end record;

Container

-- Container attributes including its widgets

: Container_Type;

-----------------------------------------------------------------------------

function Add

( Widget : in Widget_Record

--will want a general type

) return Boolean is

-- Note: The initialized Visible condition of the Widget is contained in

-- the record.

begin -- Add

if Container.Data.Count < Widget_Count_Type'last then

Container.Data.Count := Container.Data.Count + 1;

Container.Data.List(Container.Data.Count) := Widget;

return True;

else

return False; -- widget not added

end if;

end Add;

procedure Hide is

-- Hide all the widgets of the container but leave the status of the

-- individual widgets unchanged so when the container is made visible

-- the widgets that were hidden prior to hiding the container will

-- remain hidden.

begin -- Hide

for I in 1..Container.Data.Count loop

Gtk.Widget.Hide( Gtk.Widget.Gtk_Widget(Container.Data.List(I).Widget) );

end loop;

Container.Visible := False;

end Hide;

procedure Hide

( Widget : in Gtk.Button.Gtk_Button

) is

-- Hide the Widget

use type Gtk.Button.Gtk_Button;

begin -- Hide

for I in 1..Container.Data.Count loop

if Widget = Container.Data.List(I).Widget then

if Container.Data.List(I).Visible then

Gtk.Widget.Hide( Gtk.Widget.Gtk_Widget(Widget) );

Container.Data.List(I).Visible := False;

exit; -- loop

--else already hidden

end if;

end loop;

end Hide;

procedure Show is

-- Show all the widgets of the container that weren't hidden before the

-- Hide of the container was done

begin -- Show

if not Container.Visible then

for I in 1..Container.Data.Count loop

if Container.Data.List(I).Visible then -- reshow the widget

Gtk.Widget.Show( Gtk.Widget.Gtk_Widget(Container.Data.List(I).Widget) );

--else keep hidden

end if;

end loop;

end if;

Container.Visible := True;

end Show;

procedure Show

( Widget : in Gtk.Button.Gtk_Button

) is

-- Show the Widget. Refresh it as supposed to be visible already.

use type Gtk.Button.Gtk_Button;

begin -- Show

for I in 1..Container.Data.Count loop

if Widget = Container.Data.List(I).Widget then

Gtk.Widget.Show( Gtk.Widget.Gtk_Widget(Widget) );

Container.Data.List(I).Visible := True;

exit; -- loop

end if;

end loop;

end Show;

function Is_Visible

return Boolean is

-- Returns whether the container is set to be visible

begin -- Is_Visible

return Container.Visible;

end Is_Visible;

function Is_Visible

( Widget : in Gtk.Button.Gtk_Button

-- Widget being checked

) return Boolean is

-- Returns whether the widget is set to be visible

use type Gtk.Button.Gtk_Button;

begin -- Is_Visible

for I in 1..Container.Data.Count loop

if Widget = Container.Data.List(I).Widget then

return Container.Data.List(I).Visible;

end if;

end loop;

return False; -- widget isn't in container

end Is_Visible;

begin -- at instantiation

Container.Visible := False; -- assume container hidden

Container.Data.Count := 0;

end Gtk_Container;

my head stuck in the computer

Sunday, February 5, 2017

GtkAda Button Clicks and Containers

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