ch7.calculator.rar_linux计算器_linux计算器gtk

/* * Calculator.c * * Example showing different widgets in use. * */ #include "gtk/gtk.h" #include <math.h> #include <ctype.h> static float num1 = 0; static char lastChar = (char) 0; static char prevCmd = (char) 0; #define BUF_SIZE 88 /* * --- data structure to keep track of the calculator buttons. */ typedef struct { char *szLabel; /* --- Label display on button --- */ int row; /* --- Row to place the button --- */ int col; /* --- Column to place the button --- */ GtkWidget *widget; /* --- Handle to the button --- */ } typCalculatorButton; /* * --- This is the button list. Each button is documented here so * we can access it. */ typCalculatorButton buttonList [] = { {"C", 1, 0, NULL}, /* --- Clear --- */ {"CE", 1, 1, NULL}, /* --- Clear --- */ {"/", 1, 3, NULL}, /* --- Division --- */ {"7", 2, 0, NULL}, /* --- Digit --- */ {"8", 2, 1, NULL}, /* --- Digit --- */ {"9", 2, 2, NULL}, /* --- Digit --- */ {"*", 2, 3, NULL}, /* --- Multiplication --- */ {"%", 2, 4, NULL}, /* --- Percent --- */ {"4", 3, 0, NULL}, /* --- Digit --- */ {"5", 3, 1, NULL}, /* --- Digit --- */ {"6", 3, 2, NULL}, /* --- Digit --- */ {"-", 3, 3, NULL}, /* --- Subtraction --- */ {"1/x", 3, 4, NULL}, /* --- 1/x --- */ {"1", 4, 0, NULL}, /* --- Digit --- */ {"2", 4, 1, NULL}, /* --- Digit --- */ {"3", 4, 2, NULL}, /* --- Digit --- */ {"+", 4, 3, NULL}, /* --- Addition --- */ {"sqrt",4, 4, NULL}, /* --- Square root --- */ {"+/-", 5, 0, NULL}, /* --- Negate value --- */ {"0", 5, 1, NULL}, /* --- zero --- */ {".", 5, 2, NULL}, /* --- Decimal --- */ {"=", 5, 3, NULL}, /* --- Equals/total --- */ {"x^2", 5, 4, NULL}, /* --- Squared --- */ }; /* * --- Number of buttons in the data structure. */ int nButtons = sizeof (buttonList) / sizeof (typCalculatorButton); /* --- This is the LCD panel - the results --- */ GtkWidget *label; /* * CloseAppWindow * * The window is closing down, end the gtk loop */ gint CloseAppWindow (GtkWidget *widget, gpointer data) { gtk_main_quit (); return (FALSE); } /* * TrimTrailingZeros * * Get rid of trailing zeros * Takes the string and removes the trailing zeros. */ void TrimTrailingZeros (char *szDigits) { int nIndex; int bDecimal = FALSE; int nPos = -1; /* --- Loop through the string. --- */ for (nIndex = 0; nIndex < strlen (szDigits); nIndex++) { /* --- Is this a decimal? --- */ if (szDigits[nIndex] == '.') { bDecimal = TRUE; } /* --- If we're on the right side of the decimal... --- */ if (bDecimal) { /* --- A zero? Hmm... from this point on? --- */ if (szDigits[nIndex] == '0') { /* --- If we don't have a point yet... --- */ if (nPos < 0) { /* --- Save this as a point. --- */ nPos = nIndex; } } else { /* --- Clear it. Bad point. --- */ nPos = -1; } } } /* --- Truncate the field. --- */ if (nPos > 0) { szDigits[nPos] = (char) 0; } } /* * TrimLeadingZeros * * Trim the leading zeros. * * Converts numbers like "0000012" to "12" */ void TrimLeadingZeros (char *szDigits) { int nPos; if (szDigits == NULL) return; /* --- While we have a combination a digit in front --- */ for (nPos = 0; (szDigits[nPos] && szDigits[nPos] == '0'); nPos++) { /* --- If the digit is a zero and next char is a digit --- */ if (isdigit (szDigits[nPos+1])) { /* --- Blank the field. --- */ szDigits[nPos] = ' '; } } } /* * Command * * Returns true if the character is a two digit command. */ int Command (char ch) { switch (ch) { case '+': case '-': case '/': case '*': case '=': return (TRUE); } return (FALSE); } /* * FloatingPointChar * * Returns true if the character is any of [0123456789.] */ int FloatingPointChar (char ch) { return (isdigit (ch) || ch == '.'); } /* * key_press * * Handle the button "key_press" event. * * Function looks for the keystroke in the calculator * data structure and (if a match is found) presses the * button that matches the keystroke for the user. It * keeps our code small since we only have to handle the * button_clicked events. */ void key_press (GtkWidget *widget, GdkEventKey *event, gpointer data) { int nIndex; /* --- Search through the buttons --- */ for (nIndex = 0; nIndex < nButtons; nIndex++) { /* --- If the keystroke is the first character of a button AND --- */ /* --- the button label length is one. --- */ if (event->keyval == buttonList[nIndex].szLabel[0] && buttonList[nIndex].szLabel[1] == (char) 0) { /* --- Set focus to that button --- */ gtk_widget_grab_focus (buttonList[nIndex].widget); /* --- Make like the button was clicked to do processing. --- */ gtk_button_clicked (GTK_BUTTON (buttonList[nIndex].widget)); return; } } } /* * HandleDigit * * Digit button was pressed, deal with it. How it * is dealt with depends on the situation. */ void HandleDigit (char *str, char ch) { char *labelText; char buffer[BUF_SIZE]; int len; /* --- And they just did a command --- */ if (Command (lastChar)) { /* --- Clear the digit field --- */ gtk_label_set (GTK_LABEL (label), ""); /* --- If they did a computation --- */ if (lastChar == '=') { /* --- Clear out the command --- */ lastChar = (char) 0; prevCmd = (char) 0; } } /* --- Get the buffer in the led --- */ gtk_label_get (GTK_LABEL (label), &labelText); strcpy (buffer, labelText); /* --- Add the new character on it. --- */ len = strlen (buffer); buffer[len] = (gchar) ch; buffer[len+1] = (gchar) 0; /* --- Trim leading zeros. --- */ TrimLeadingZeros (buffer); /* --- Add digit to field. --- */ gtk_label_set (GTK_LABEL (label), (char *) buffer); } /* * MaybeUnary * * str * * Check to see if the user hit a unary operator button - * like %, sqrt, 1/x, etc that should be dealt with NOW * not later. */ void MaybeUnaryOperation (char *str) { char *labelText; char buffer[BUF_SIZE]; float num2; /* --- Get number in the field. --- */ gtk_label_get (GTK_LABEL (label), &labelText); num2 = atof (labelText); /* --- Percentage? --- */ if (strcmp (str, "%") == 0) { num2 = num2 / 100; /* --- Trying for 1/x? --- */ } else if (strcmp (str, "1/x") == 0) { /* --- Can't divide by zero. --- */ if (num2 == 0) { /*Error (); */ return; } num2 = 1 / num2; /* --- Calculate sqrt --- */ } else if (strcmp (str, "sqrt") == 0) { num2 = sqrt ((double) num2); /* --- Calculate square --- */ } else if (strcmp (str, "x^2") == 0) { num2 = num2 * num2; } /* --- Put the number back. --- */ sprintf (buffer, "%f", (float) num2); TrimTrailingZeros (buffer); TrimLeadingZeros (buffer); gtk_label_set (GTK_LABEL (label), buffer); } void HandleBinaryOperation () { char buffer[BUF_SIZE]; char *labelText; float num2; /* --- Get number in the field. --- */ gtk_label_get (GTK_LABEL (label), &labelText); num2 = atof (labelText); /* --- Calculate based on previous command. --- */ switch (prevCmd) { case '+': num1 = num