Added real-time LaTex rendering in LatexDialog

src/control/LatexController.cpp

@@ -11,26 +11,26 @@
 #include <Stacktrace.h>
 
 #include <boost/filesystem.hpp>
+#include "pixbuf-utils.h"
 
 #include <iostream>
 using std::cout;
 using std::endl;
 
-
-LatexController::LatexController(Control* control)
- : control(control),
-   texArea(0),
-   posx(0),
-   posy(0),
-   imgwidth(0),
-   imgheight(0),
-   doc(control->getDocument()),
-   view(NULL),
-   layer(NULL),
-   // .png will be appended automatically => tex.png
-   texImage(Util::getConfigFile("tex").string()),
-   selectedTexImage(NULL),
-   selectedText(NULL)
+LatexController::LatexController(Control *control)
+	: control(control),
+	  texArea(0),
+	  posx(0),
+	  posy(0),
+	  imgwidth(0),
+	  imgheight(0),
+	  doc(control->getDocument()),
+	  view(NULL),
+	  layer(NULL),
+	  // .png will be appended automatically => tex.png
+	  texImage(Util::getConfigFile("tex").string()),
+	  selectedTexImage(NULL),
+	  selectedText(NULL)
 {
 	XOJ_INIT_TYPE(LatexController);
 }
@@ -60,7 +60,7 @@ bool LatexController::findTexExecutable()
 		return true;
 	}
 
-	gchar* mathtex = g_find_program_in_path("mathtex-xournalpp.cgi");
+	gchar *mathtex = g_find_program_in_path("mathtex-xournalpp.cgi");
 	if (!mathtex)
 	{
 		return false;
@@ -72,7 +72,6 @@ bool LatexController::findTexExecutable()
 	return true;
 }
 
-
 /**
  * Run LaTeX Command
  */
@@ -108,13 +107,10 @@ bool LatexController::runCommand()
 	{
 		texres = "1000";
 	}
-
-	string command = FS(bl::format("{1} -m 0 \"\\png\\usepackage{{color}}\\color{{{2}}}\\dpi{{{3}}}\\normalsize {4}\" -o {5}")
-						% binTex % "black" % texres
-						% g_strescape(currentTex.c_str(), NULL) % texImage);
+	string command = FS(bl::format("{1} -m 0 \"\\png\\usepackage{{color}}\\color{{{2}}}\\dpi{{{3}}}\\normalsize {4}\" -o {5}") % binTex % fontcolour % texres % g_strescape(currentTex.c_str(), NULL) % texImage);
 
 	gint rt = 0;
-	void(*texhandler)(int) = signal(SIGCHLD, SIG_DFL);
+	void (*texhandler)(int) = signal(SIGCHLD, SIG_DFL);
 	gboolean success = g_spawn_command_line_sync(command.c_str(), NULL, NULL, &rt, NULL);
 	signal(SIGCHLD, texhandler);
 
@@ -152,7 +148,7 @@ void LatexController::findSelectedTexElement()
 	if (selectedTexImage || selectedText)
 	{
 		// this will get the position of the Latex properly
-		EditSelection* theSelection = control->getWindow()->getXournal()->getSelection();
+		EditSelection *theSelection = control->getWindow()->getXournal()->getSelection();
 		posx = theSelection->getXOnView();
 		posy = theSelection->getYOnView();
 
@@ -173,7 +169,11 @@ void LatexController::findSelectedTexElement()
 
 		texArea = imgwidth * imgheight;
 	}
-
+	if (initalTex.empty())
+	{
+		initalTex = "x^2";
+	}
+	currentTex = initalTex;
 	doc->unlock();
 
 	// need to do this otherwise we can't remove the image for its replacement
@@ -184,44 +184,87 @@ void LatexController::showTexEditDialog()
 {
 	XOJ_CHECK_TYPE(LatexController);
 
-	LatexDialog* dlg = new LatexDialog(control->getGladeSearchPath());
+	dlg = new LatexDialog(control->getGladeSearchPath());
+	//For 'real time' LaTex rendering in the dialog
+	g_signal_connect(dlg->getTexBox(), "changed", G_CALLBACK(this->handleTexChanged), gpointer(this));
 	dlg->setTex(initalTex);
+	//The controller owns the tempRender because, on signal changed, he has to handle the old/new renders
+	insertTexImage(true);
+	dlg->setTempRender(temporaryRender->getImage());
 	dlg->show(GTK_WINDOW(control->getWindow()->getWindow()));
+	deletePreviousRender();
 	currentTex = dlg->getTex();
 	currentTex += " ";
 
 	delete dlg;
 }
 
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Text-changed handler: when the Entry in the dialog changes,
+ * this handler updates currentTex, removes the previous existing render and creates
+ * a new one. We need to do it through 'thisContr' because signal handlers
+ * cannot directly access non-static methods and non-static fields such as
+ * 'dlg' so we need to wrap all the dlg method inside small methods in 'thisContr'
+ * 
+ */
+void LatexController::handleTexChanged(GtkWidget *widget, gpointer data)
+{
+	LatexController *thisContr = ((LatexController *)data);
+
+	thisContr->setCurrentTex(gtk_entry_get_text(GTK_ENTRY(widget)));
+	thisContr->deletePreviousRender();
+	thisContr->runCommand();
+	thisContr->insertTexImage(true);
+	thisContr->setImageInDialog(thisContr->getTemporaryRender()->getImage());
+}
+
+TexImage* LatexController::getTemporaryRender(){
+	return this->temporaryRender;
+}
+
+void LatexController::setImageInDialog(cairo_surface_t *image)
+{
+	dlg->setTempRender(image);
+}
+
+void LatexController::deletePreviousRender()
+{
+	delete temporaryRender;
+}
+
+void LatexController::setCurrentTex(string currentTex)
+{
+	this->currentTex = currentTex;
+}
+
 void LatexController::deleteOldImage()
 {
 	XOJ_CHECK_TYPE(LatexController);
 
 	if (selectedTexImage)
 	{
-		EditSelection* selection = new EditSelection(control->getUndoRedoHandler(), selectedTexImage, view, page);
+		EditSelection *selection = new EditSelection(control->getUndoRedoHandler(), selectedTexImage, view, page);
 		view->getXournal()->deleteSelection(selection);
 		delete selection;
 		selectedTexImage = NULL;
 	}
 	else if (selectedText)
 	{
-		EditSelection* selection = new EditSelection(control->getUndoRedoHandler(), selectedText, view, page);
+		EditSelection *selection = new EditSelection(control->getUndoRedoHandler(), selectedText, view, page);
 		view->getXournal()->deleteSelection(selection);
 		delete selection;
 		selectedText = NULL;
 	}
 }
 
-void LatexController::insertTexImage()
+void LatexController::insertTexImage(bool forTemporaryRender)
 {
 	XOJ_CHECK_TYPE(LatexController);
 
 	string imgPath = texImage + ".png";
-
-	GFile* mygfile = g_file_new_for_path(imgPath.c_str());
-	GError* err = NULL;
-	GFileInputStream* in = g_file_read(mygfile, NULL, &err);
+	GFile *mygfile = g_file_new_for_path(imgPath.c_str());
+	GError *err = NULL;
+	GFileInputStream *in = g_file_read(mygfile, NULL, &err);
 	g_object_unref(mygfile);
 
 	if (err)
@@ -231,12 +274,12 @@ void LatexController::insertTexImage()
 		return;
 	}
 
-	GdkPixbuf* pixbuf = gdk_pixbuf_new_from_stream(G_INPUT_STREAM(in), NULL, &err);
+	GdkPixbuf *pixbuf = gdk_pixbuf_new_from_stream(G_INPUT_STREAM(in), NULL, &err);
 	g_input_stream_close(G_INPUT_STREAM(in), NULL, NULL);
 
 	deleteOldImage();
 
-	TexImage* img = new TexImage();
+	TexImage *img = new TexImage();
 	img->setX(posx);
 	img->setY(posy);
 	img->setImage(pixbuf);
@@ -244,7 +287,7 @@ void LatexController::insertTexImage()
 
 	if (imgheight)
 	{
-		double ratio = (gdouble) gdk_pixbuf_get_width(pixbuf) / gdk_pixbuf_get_height(pixbuf);
+		double ratio = (gdouble)gdk_pixbuf_get_width(pixbuf) / gdk_pixbuf_get_height(pixbuf);
 		if (ratio == 0)
 		{
 			if (imgwidth == 0)
@@ -268,6 +311,14 @@ void LatexController::insertTexImage()
 		img->setHeight(gdk_pixbuf_get_height(pixbuf));
 	}
 
+	//Calling this function for 'on-the-go' LaTex render too, so
+	//if this is that case, return to the caller at this point
+	if (forTemporaryRender)
+	{
+		this->temporaryRender = img;
+		return;
+	}
+
 	doc->lock();
 	layer->addElement(img);
 	view->rerenderElement(img);
@@ -276,8 +327,10 @@ void LatexController::insertTexImage()
 	control->getUndoRedoHandler()->addUndoAction(new InsertUndoAction(page, layer, img));
 
 	// Select element
-	EditSelection* selection = new EditSelection(control->getUndoRedoHandler(), img, view, page);
+	EditSelection *selection = new EditSelection(control->getUndoRedoHandler(), img, view, page);
 	view->getXournal()->setSelection(selection);
+	
+	return;
 }
 
 void LatexController::run()
@@ -310,6 +363,7 @@ void LatexController::run()
 		return;
 	}
 
-	insertTexImage();
+	//False, because it's not for temporary render but this time
+	//we add it to the document
+	insertTexImage(false);
 }
-

src/control/LatexController.h

@@ -18,7 +18,7 @@
 #include "model/Text.h"
 
 #include <XournalType.h>
-
+#include "gui/dialog/LatexDialog.h"
 #include <string>
 using std::string;
 
@@ -49,14 +49,45 @@ private:
 	 */
 	void findSelectedTexElement();
 
+	/**
+	 * If a previous image/text is selected, delete it 
+	 */
+	void deleteOldImage();
+
 	/**
 	 * Run LaTeX Command
 	 */
 	bool runCommand();
 
+	/**
+	 * Show the LaTex Editor dialog
+	 */
 	void showTexEditDialog();
-	void insertTexImage();
-	void deleteOldImage();
+
+	/**
+	 * Signal handler, updates the rendered image when the text in the editor changes
+	 */
+	static void handleTexChanged(GtkWidget* widget, gpointer data);
+
+	/*******/
+	//Wrappers for signal handler who can't access non-static fields 
+	//(see implementation for further explanation)
+	TexImage* getTemporaryRender();
+	void setImageInDialog(cairo_surface_t* image);
+	void deletePreviousRender();
+	void setCurrentTex(string currentTex);
+	/*******/
+
+	/**
+	 * Actual image creation, if 'forTemporaryRender' is true, it does not
+	 * add the image to the doc because it means that it has been called
+	 * during the render in the Editor dialog
+	 */
+	void insertTexImage(bool forTemporaryRender);
+	
+	
+	
+	
 
 private:
 	XOJ_TYPE_ATTRIB;
@@ -128,6 +159,21 @@ private:
 	 */
 	string texImage;
 
+	/**
+	 * Previously existin TexImage
+	 */
 	TexImage* selectedTexImage;
+
 	Text* selectedText;
+
+	/**
+	 * LaTex editor dialog
+	 */
+	LatexDialog* dlg;
+
+	/**
+	 * The controller holds the 'on-the-go' render in order
+	 * to be able to delete it when a new render is created
+	 */
+	TexImage* temporaryRender;
 };

src/gui/dialog/LatexDialog.cpp

@@ -1,16 +1,21 @@
 #include "LatexDialog.h"
 
-LatexDialog::LatexDialog(GladeSearchpath* gladeSearchPath)
- : GladeGui(gladeSearchPath, "texdialog.glade", "texDialog")
+LatexDialog::LatexDialog(GladeSearchpath *gladeSearchPath)
+	: GladeGui(gladeSearchPath, "texdialog.glade", "texDialog")
 {
 	XOJ_INIT_TYPE(LatexDialog);
 
 	this->texBox = get("texEntry");
+	this->texTempRender = get("texImage");
 
 	// increase the maximum length to something reasonable.
 	gtk_entry_set_max_length(GTK_ENTRY(this->texBox), 500);
 
-	gtk_widget_show(this->texBox);
+	//Background color for the temporary render, default is white because
+	//on dark themed DE the LaTex is hard to read
+	GtkCssProvider* cssProvider = gtk_css_provider_new();
+	gtk_css_provider_load_from_data(cssProvider, "*{background-color:white;padding:10px;}", -1, NULL);
+	gtk_style_context_add_provider(gtk_widget_get_style_context(this->texTempRender), GTK_STYLE_PROVIDER(cssProvider), GTK_STYLE_PROVIDER_PRIORITY_APPLICATION);
 }
 
 LatexDialog::~LatexDialog()
@@ -30,6 +35,27 @@ string LatexDialog::getTex()
 	return this->theLatex;
 }
 
+void LatexDialog::setTempRender(cairo_surface_t *cairoTexTempRender)
+{
+	XOJ_CHECK_TYPE(LatexDialog);
+	this->cairoTexTempRender = cairoTexTempRender;
+	//Every time the controller updates the temporary render, we update
+	//our corresponding GtkWidget
+	gtk_image_set_from_surface(GTK_IMAGE(this->texTempRender), this->cairoTexTempRender);
+}
+
+cairo_surface_t *LatexDialog::getTempRender()
+{
+	XOJ_CHECK_TYPE(LatexDialog);
+	return this->cairoTexTempRender;
+}
+
+GtkWidget *LatexDialog::getTexBox()
+{
+	XOJ_CHECK_TYPE(LatexDialog);
+	return this->texBox;
+}
+
 void LatexDialog::save()
 {
 	XOJ_CHECK_TYPE(LatexDialog);
@@ -48,10 +74,9 @@ void LatexDialog::load()
 	gtk_entry_set_text(GTK_ENTRY(this->texBox), this->theLatex.c_str());
 }
 
-void LatexDialog::show(GtkWindow* parent)
+void LatexDialog::show(GtkWindow *parent)
 {
 	XOJ_CHECK_TYPE(LatexDialog);
-
 	this->load();
 	gtk_window_set_transient_for(GTK_WINDOW(this->window), parent);
 	int res = gtk_dialog_run(GTK_DIALOG(this->window));

src/gui/dialog/LatexDialog.h

@@ -15,24 +15,41 @@
 
 #include "gui/GladeGui.h"
 
+#include "model/TexImage.h"
+
 #include <XournalType.h>
 
 class LatexDialog : public GladeGui
 {
-public:
-	LatexDialog(GladeSearchpath* gladeSearchPath);
+  public:
+	LatexDialog(GladeSearchpath *gladeSearchPath);
 	virtual ~LatexDialog();
 
-public:
-	virtual void show(GtkWindow* parent);
+  public:
+	virtual void show(GtkWindow *parent);
 	void save();
 	void load();
+
+	//Set and retrieve text from text box
 	void setTex(string texString);
 	string getTex();
+	
+	//Set and retrieve temporary Tex render
+	void setTempRender(cairo_surface_t *cairoTexTempRender);
+	cairo_surface_t *getTempRender();
 
+	//Necessary for the controller in order to connect the 'text-changed'
+	//signal handler
+	GtkWidget* getTexBox();
 
-private:
+  private:
 	XOJ_TYPE_ATTRIB;
-	GtkWidget* texBox;
+	
+	//Temporary render
+	GtkWidget *texTempRender;
+	cairo_surface_t *cairoTexTempRender;
+	
+	//Text field
+	GtkWidget *texBox;
 	string theLatex;
 };

ui/texdialog.glade

@@ -83,6 +83,19 @@
             <property name="expand">False</property>
             <property name="fill">True</property>
             <property name="position">3</property>
+
+          </packing>
+        </child>
+        <child>
+          <object class="GtkImage" id="texImage">
+            <property name="visible">True</property>
+            <property name="can_focus">False</property>
+          </object>
+          <packing>
+            <property name="expand">True</property>
+            <property name="fill">True</property>
+            <property name="padding">12</property>
+            <property name="position">2</property>
           </packing>
         </child>
       </object>