Sorry about the mega-patch.

This is a work-in-progress, code is currently broken.
(Some actions, and notably, the header, are missing.)

1 files changed, 88 insertions, 91 deletions

diff --git a/Panel.c b/Panel.c
index 4355b1e2..8982cc2e 100644
--- a/Panel.c
+++ b/Panel.c
@@ -28,9 +28,11 @@ in the source distribution for its full text.
 typedef struct Panel_ Panel;
 
 typedef enum HandlerResult_ {
-   HANDLED,
-   IGNORED,
-   BREAK_LOOP
+   HANDLED     = 0x00,
+   IGNORED     = 0x01,
+   BREAK_LOOP  = 0x02,
+   REFRESH     = 0x04,
+   RECALCULATE = 0x08,
 } HandlerResult;
 
 #define EVENT_SETSELECTED -1
@@ -54,7 +56,7 @@ struct Panel_ {
    Vector* items;
    int selected;
    int oldSelected;
-   char* eventHandlerBuffer;
+   void* eventHandlerState;
    int scrollV;
    short scrollH;
    bool needsRedraw;
@@ -102,7 +104,7 @@ void Panel_init(Panel* this, int x, int y, int w, int h, ObjectClass* type, bool
    this->y = y;
    this->w = w;
    this->h = h;
-   this->eventHandlerBuffer = NULL;
+   this->eventHandlerState = NULL;
    this->items = Vector_new(type, owner, DEFAULT_SIZE);
    this->scrollV = 0;
    this->scrollH = 0;
@@ -114,7 +116,7 @@ void Panel_init(Panel* this, int x, int y, int w, int h, ObjectClass* type, bool
 
 void Panel_done(Panel* this) {
    assert (this != NULL);
-   free(this->eventHandlerBuffer);
+   free(this->eventHandlerState);
    Vector_delete(this->items);
    RichString_end(this->header);
 }
@@ -246,30 +248,11 @@ void Panel_setSelected(Panel* this, int selected) {
 void Panel_draw(Panel* this, bool focus) {
    assert (this != NULL);
 
-   int itemCount = Vector_size(this->items);
+   int size = Vector_size(this->items);
    int scrollH = this->scrollH;
-   int y = this->y; int x = this->x;
-   int first = this->scrollV;
-   if (itemCount > this->h && first > itemCount - this->h) {
-      first = itemCount - this->h;
-      this->scrollV = first;
-   }
-   int last = MIN(itemCount, first + MIN(itemCount, this->h));
-   if (this->selected < first) {
-      first = this->selected;
-      this->scrollV = first;
-      this->needsRedraw = true;
-   }
-   if (this->selected >= last) {
-      last = MIN(itemCount, this->selected + 1);
-      first = last - this->h;
-      this->scrollV = first;
-      this->needsRedraw = true;
-   }
-   if (first < 0)
-      first = 0;
-   if (last > itemCount)
-      last = itemCount;
+   int y = this->y;
+   int x = this->x;
+   int h = this->h;
 
    int headerLen = RichString_sizeVal(this->header);
    if (headerLen > 0) {
@@ -285,14 +268,34 @@ void Panel_draw(Panel* this, bool focus) {
       attrset(CRT_colors[RESET_COLOR]);
       y++;
    }
-   
+
+   // ensure scroll area is on screen
+   if (this->scrollV < 0) {
+      this->scrollV = 0;
+      this->needsRedraw = true;
+   } else if (this->scrollV >= size) {
+      this->scrollV = MAX(size - 1, 0);
+      this->needsRedraw = true;
+   }
+   // ensure selection is on screen
+   if (this->selected < this->scrollV) {
+      this->scrollV = this->selected;
+      this->needsRedraw = true;
+   } else if (this->selected >= this->scrollV + h) {
+      this->scrollV = this->selected - h + 1;
+      this->needsRedraw = true;
+   }
+
+   int first = this->scrollV;
+   int upTo = MIN(first + h, size);
+
    int highlight = focus
                  ? CRT_colors[PANEL_HIGHLIGHT_FOCUS]
                  : CRT_colors[PANEL_HIGHLIGHT_UNFOCUS];
 
    if (this->needsRedraw) {
-
-      for(int i = first, j = 0; j < this->h && i < last; i++, j++) {
+      int line = 0;
+      for(int i = first; line < h && i < upTo; i++) {
          Object* itemObj = Vector_get(this->items, i);
          assert(itemObj); if(!itemObj) continue;
          RichString_begin(item);
@@ -304,15 +307,18 @@ void Panel_draw(Panel* this, bool focus) {
             attrset(highlight);
             RichString_setAttr(&item, highlight);
          }
-         mvhline(y + j, x, ' ', this->w);
+         mvhline(y + line, x, ' ', this->w);
          if (amt > 0)
-            RichString_printoffnVal(item, y+j, x, scrollH, amt);
+            RichString_printoffnVal(item, y + line, x, scrollH, amt);
          if (selected)
             attrset(CRT_colors[RESET_COLOR]);
          RichString_end(item);
+         line++;
+      }
+      while (line < h) {
+         mvhline(y + line, x, ' ', this->w);
+         line++;
       }
-      for (int i = y + (last - first); i < y + this->h; i++)
-         mvhline(i, x+0, ' ', this->w);
       this->needsRedraw = false;
 
    } else {
@@ -325,15 +331,15 @@ void Panel_draw(Panel* this, bool focus) {
       RichString_begin(new);
       Object_display(newObj, &new);
       int newLen = RichString_sizeVal(new);
-      mvhline(y+ this->oldSelected - this->scrollV, x+0, ' ', this->w);
+      mvhline(y+ this->oldSelected - first, x+0, ' ', this->w);
       if (scrollH < oldLen)
-         RichString_printoffnVal(old, y+this->oldSelected - this->scrollV, x,
+         RichString_printoffnVal(old, y+this->oldSelected - first, x,
             scrollH, MIN(oldLen - scrollH, this->w));
       attrset(highlight);
-      mvhline(y+this->selected - this->scrollV, x+0, ' ', this->w);
+      mvhline(y+this->selected - first, x+0, ' ', this->w);
       RichString_setAttr(&new, highlight);
       if (scrollH < newLen)
-         RichString_printoffnVal(new, y+this->selected - this->scrollV, x,
+         RichString_printoffnVal(new, y+this->selected - first, x,
             scrollH, MIN(newLen - scrollH, this->w));
       attrset(CRT_colors[RESET_COLOR]);
       RichString_end(new);
@@ -345,38 +351,26 @@ void Panel_draw(Panel* this, bool focus) {
 
 bool Panel_onKey(Panel* this, int key) {
    assert (this != NULL);
+   
+   int size = Vector_size(this->items);
    switch (key) {
    case KEY_DOWN:
    case KEY_CTRLN:
-      if (this->selected + 1 < Vector_size(this->items))
-         this->selected++;
-      return true;
+      this->selected++;
+      break;
    case KEY_UP:
    case KEY_CTRLP:
-      if (this->selected > 0)
-         this->selected--;
-      return true;
+      this->selected--;
+      break;
    #ifdef KEY_C_DOWN
    case KEY_C_DOWN:
-      if (this->selected + 1 < Vector_size(this->items)) {
-         this->selected++;
-         if (this->scrollV < Vector_size(this->items) - this->h) {
-            this->scrollV++;
-            this->needsRedraw = true;
-         }
-      }
-      return true;
+      this->selected++;
+      break;
    #endif
    #ifdef KEY_C_UP
    case KEY_C_UP:
-      if (this->selected > 0) {
-         this->selected--;
-         if (this->scrollV > 0) {
-            this->scrollV--;
-            this->needsRedraw = true;
-         }
-      }
-      return true;
+      this->selected--;
+      break;
    #endif
    case KEY_LEFT:
    case KEY_CTRLB:
@@ -384,71 +378,74 @@ bool Panel_onKey(Panel* this, int key) {
          this->scrollH -= CRT_scrollHAmount;
          this->needsRedraw = true;
       }
-      return true;
+      break;
    case KEY_RIGHT:
    case KEY_CTRLF:
       this->scrollH += CRT_scrollHAmount;
       this->needsRedraw = true;
-      return true;
+      break;
    case KEY_PPAGE:
       this->selected -= (this->h - 1);
       this->scrollV -= (this->h - 1);
-      if (this->selected < 0)
-         this->selected = 0;
-      if (this->scrollV < 0)
-         this->scrollV = 0;
       this->needsRedraw = true;
-      return true;
+      break;
    case KEY_NPAGE:
       this->selected += (this->h - 1);
-      int size = Vector_size(this->items);
-      if (this->selected < 0)
-         this->selected = 0;
-      if (this->selected >= size)
-         this->selected = size - 1;
       this->scrollV += (this->h - 1);
-      if (this->scrollV >= MAX(0, size - this->h))
-         this->scrollV = MAX(0, size - this->h - 1);
       this->needsRedraw = true;
-      return true;
+      break;
    case KEY_HOME:
       this->selected = 0;
-      return true;
+      break;
    case KEY_END:
-      this->selected = Vector_size(this->items) - 1;
-      return true;
+      this->selected = size - 1;
+      break;
+   default:
+      return false;
+   }
+
+   // ensure selection within bounds
+   if (this->selected < 0) {
+      this->selected = 0;
+      this->needsRedraw = true;
+   } else if (this->selected >= size) {   
+      this->selected = size - 1;
+      this->needsRedraw = true;
    }
-   return false;
+   return true;
 }
 
 
 HandlerResult Panel_selectByTyping(Panel* this, int ch) {
    int size = Panel_size(this);
-   if (!this->eventHandlerBuffer)
-      this->eventHandlerBuffer = calloc(100, 1);
+   if (!this->eventHandlerState)
+      this->eventHandlerState = calloc(100, 1);
+   char* buffer = this->eventHandlerState;
 
    if (isalnum(ch)) {
-      int len = strlen(this->eventHandlerBuffer);
+      int len = strlen(buffer);
       if (len < 99) {
-         this->eventHandlerBuffer[len] = ch;
-         this->eventHandlerBuffer[len+1] = '\0';
+         buffer[len] = ch;
+         buffer[len+1] = '\0';
       }
       for (int try = 0; try < 2; try++) {
-         len = strlen(this->eventHandlerBuffer);
+         len = strlen(buffer);
          for (int i = 0; i < size; i++) {
             char* cur = ((ListItem*) Panel_get(this, i))->value;
             while (*cur == ' ') cur++;
-            if (strncasecmp(cur, this->eventHandlerBuffer, len) == 0) {
+            if (strncasecmp(cur, buffer, len) == 0) {
                Panel_setSelected(this, i);
                return HANDLED;
             }
          }
-         this->eventHandlerBuffer[0] = ch;
-         this->eventHandlerBuffer[1] = '\0';
+         // if current word did not match,
+         // retry considering the character the start of a new word.
+         buffer[0] = ch;
+         buffer[1] = '\0';
       }
       return HANDLED;
    } else if (ch != ERR) {
-      this->eventHandlerBuffer[0] = '\0';
+      buffer[0] = '\0';
    }
    if (ch == 13) {
       return BREAK_LOOP;