2016 Update

Task/GUI-component-interaction/00DESCRIPTION

@@ -24,17 +24,23 @@ Typically, the following is needed:
 * read and check input from the user
 * pop up dialogs to query the user for further information
 
-The task: For a minimal "application", write a program that presents
-a form with three components to the user:
-A numeric input field ("Value") and two buttons ("increment" and "random").
+
+;Task:
+For a minimal "application", write a program that presents a form with three components to the user:
+::* a numeric input field ("Value")
+::* a button ("increment")
+::* a button ("random")
+
 
 The field is initialized to zero.
+
 The user may manually enter a new value into the field,
 or increment its value with the "increment" button.
+
 Entering a non-numeric value should be either impossible,
 or issue an error message.
 
 Pressing the "random" button presents a confirmation dialog,
 and resets the field's value to a random value if the answer is "Yes".
 
-(This task may be regarded as an extension of the task [[Simple windowed application]]).
+(This task may be regarded as an extension of the task [[Simple windowed application]]).<br><br>

Task/GUI-component-interaction/C/gui-component-interaction-1.c

@@ -0,0 +1,48 @@
+#include <windows.h>
+#include "resource.h"
+
+BOOL CALLBACK DlgProc( HWND hwnd, UINT msg, WPARAM wPar, LPARAM lPar ) {
+    switch( msg ) {
+
+        case WM_INITDIALOG:
+            srand( GetTickCount() );
+            SetDlgItemInt( hwnd, IDC_INPUT, 0, FALSE );
+            break;
+
+        case WM_COMMAND:
+            switch( LOWORD(wPar) ) {
+                case IDC_INCREMENT: {
+                    UINT n = GetDlgItemInt( hwnd, IDC_INPUT, NULL, FALSE );
+                    SetDlgItemInt( hwnd, IDC_INPUT, ++n, FALSE );
+                    } break;
+                case IDC_RANDOM: {
+                    int reply = MessageBox( hwnd,
+                        "Do you really want to\nget a random number?",
+                        "Random input confirmation", MB_ICONQUESTION|MB_YESNO );
+                    if( reply == IDYES )
+                        SetDlgItemInt( hwnd, IDC_INPUT, rand(), FALSE );
+                    } break;
+                case IDC_QUIT:
+                    SendMessage( hwnd, WM_CLOSE, 0, 0 );
+                    break;
+                default: ;
+            }
+            break;
+
+        case WM_CLOSE: {
+            int reply = MessageBox( hwnd,
+                "Do you really want to quit?",
+                "Quit confirmation", MB_ICONQUESTION|MB_YESNO );
+            if( reply == IDYES )
+                EndDialog( hwnd, 0 );
+            } break;
+
+        default: ;
+    }
+
+    return 0;
+}
+
+int WINAPI WinMain( HINSTANCE hInst, HINSTANCE hPInst, LPSTR cmdLn, int show ) {
+    return DialogBox( hInst, MAKEINTRESOURCE(IDD_DLG), NULL, DlgProc );
+}

Task/GUI-component-interaction/C/gui-component-interaction-2.c

@@ -0,0 +1,5 @@
+#define IDD_DLG          101
+#define IDC_INPUT       1001
+#define IDC_INCREMENT   1002
+#define IDC_RANDOM      1003
+#define IDC_QUIT        1004

Task/GUI-component-interaction/C/gui-component-interaction-3.c

@@ -0,0 +1,14 @@
+#include <windows.h>
+#include "resource.h"
+
+LANGUAGE LANG_NEUTRAL, SUBLANG_NEUTRAL
+IDD_DLG DIALOG 0, 0, 154, 46
+STYLE DS_3DLOOK | DS_CENTER | DS_MODALFRAME | DS_SHELLFONT | WS_CAPTION |
+WS_VISIBLE | WS_POPUP | WS_SYSMENU
+CAPTION "GUI Component Interaction"
+FONT 12, "Ms Shell Dlg" {
+    EDITTEXT        IDC_INPUT, 7, 7, 140, 12, ES_AUTOHSCROLL | ES_NUMBER
+    PUSHBUTTON      "Increment", IDC_INCREMENT, 7, 25, 50, 14
+    PUSHBUTTON      "Random", IDC_RANDOM, 62, 25, 50, 14
+    PUSHBUTTON      "Quit", IDC_QUIT, 117, 25, 30, 14
+}

Task/GUI-component-interaction/Python/gui-component-interaction-1.py

@@ -0,0 +1,24 @@
+import random, tkMessageBox
+from Tkinter import *
+window = Tk()
+window.geometry("300x50+100+100")
+options = { "padx":5, "pady":5}
+s=StringVar()
+s.set(1)
+def increase():
+    s.set(int(s.get())+1)
+def rand():
+    if tkMessageBox.askyesno("Confirmation", "Reset to random value ?"):
+        s.set(random.randrange(0,5000))
+def update(e):
+    if not e.char.isdigit():
+        tkMessageBox.showerror('Error', 'Invalid input !')
+        return "break"
+e = Entry(text=s)
+e.grid(column=0, row=0, **options)
+e.bind('<Key>', update)
+b1 = Button(text="Increase", command=increase, **options )
+b1.grid(column=1, row=0, **options)
+b2 = Button(text="Random", command=rand, **options)
+b2.grid(column=2, row=0, **options)
+mainloop()