[client] overlay: add modal message dialog support

client/src/overlay/msg.c

@@ -0,0 +1,153 @@
+/**
+ * Looking Glass
+ * Copyright © 2017-2022 The Looking Glass Authors
+ * https://looking-glass.io
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc., 59
+ * Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include "interface/overlay.h"
+#include "cimgui.h"
+#include "overlay_utils.h"
+
+#include "common/stringutils.h"
+#include "common/stringlist.h"
+#include "ll.h"
+
+#include "../main.h"
+
+#include <string.h>
+
+struct Msg
+{
+  char * caption;
+  char * message;
+  StringList lines;
+};
+
+struct MsgState
+{
+  struct ll * messages;
+};
+
+struct MsgState l_msg = { 0 };
+
+static bool msg_init(void ** udata, const void * params)
+{
+  l_msg.messages = ll_new();
+  return true;
+}
+
+static void freeMsg(struct Msg * msg)
+{
+  free(msg->caption);
+  free(msg->message);
+  stringlist_free(&msg->lines);
+  free(msg);
+}
+
+static void msg_free(void * udata)
+{
+  struct Msg * msg;
+  while(ll_shift(l_msg.messages, (void **)&msg))
+    freeMsg(msg);
+  ll_free(l_msg.messages);
+}
+
+static bool msg_needsOverlay(void * udata)
+{
+  return ll_count(l_msg.messages) > 0;
+}
+
+static int msg_render(void * udata, bool interactive, struct Rect * windowRects,
+    int maxRects)
+{
+  struct Msg * msg;
+  if (!ll_peek_head(l_msg.messages, (void **)&msg))
+    return 0;
+
+  ImVec2 * screen = overlayGetScreenSize();
+  igSetNextWindowBgAlpha(0.8f);
+  igSetNextWindowPos((ImVec2) { screen->x * 0.5f, screen->y * 0.5f }, 0,
+    (ImVec2) { 0.5f, 0.5f });
+
+  igBegin(
+    msg->caption,
+    NULL,
+    ImGuiWindowFlags_AlwaysAutoResize | ImGuiWindowFlags_NoBringToFrontOnFocus |
+    ImGuiWindowFlags_NoSavedSettings  | ImGuiWindowFlags_NoNav |
+    ImGuiWindowFlags_NoMove           | ImGuiWindowFlags_NoCollapse
+  );
+
+  ImVec2 textSize;
+
+  const int lines = stringlist_count(msg->lines);
+  for(int i = 0; i < lines; ++i)
+  {
+    const char * line = stringlist_at(msg->lines, i);
+    igCalcTextSize(&textSize, line, NULL, false, 0.0);
+    igSetCursorPosX((igGetWindowWidth() * 0.5f) - (textSize.x * 0.5f));
+    igText("%s", stringlist_at(msg->lines, i));
+  }
+
+  igCalcTextSize(&textSize, "OK", NULL, false, 0.0);
+  ImGuiStyle * style = igGetStyle();
+  textSize.x += (style->FramePadding.x * 2.0f) * 8.0f;
+  textSize.y += (style->FramePadding.y * 2.0f) * 1.5f;
+  igSetCursorPosX((igGetWindowWidth() * 0.5f) - (textSize.x * 0.5f));
+
+  if (igButton("OK", textSize))
+  {
+    ll_shift(l_msg.messages, NULL);
+    freeMsg(msg);
+    app_invalidateOverlay(false);
+  }
+
+  overlayGetImGuiRect(windowRects);
+  igEnd();
+
+  return 1;
+}
+
+struct LG_OverlayOps LGOverlayMsg =
+{
+  .name           = "msg",
+  .init           = msg_init,
+  .free           = msg_free,
+  .needs_overlay  = msg_needsOverlay,
+  .render         = msg_render
+};
+
+bool overlayMsg_modal(void)
+{
+  return ll_count(l_msg.messages) > 0;
+}
+
+void overlayMsg_show(const char * caption, const char * fmt, va_list args)
+{
+  struct Msg * msg = malloc(sizeof(*msg));
+  msg->caption = strdup(caption);
+  msg->lines   = stringlist_new(false);
+  valloc_sprintf(&msg->message, fmt, args);
+
+  char * rest = msg->message;
+  char * token;
+  stringlist_clear(msg->lines);
+  while((token = strtok_r(rest, "\n", &rest)))
+    stringlist_push(msg->lines, token);
+
+  ll_push(l_msg.messages, msg);
+  app_invalidateOverlay(false);
+}