JKQTMathText: added support for flushleft/flushright/center-environments with linebreaks

doc/dox/whatsnew.dox

@@ -70,6 +70,7 @@ Changes, compared to  \ref page_whatsnew_V4_0_0 "v4.0.0" include:
     <li>NEW: added \c \\unicode{HEX} and \c \\utfeight{HEX} instruction to draw unicide characters by code</li>
     <li>NEW: JKQTMathTextVerticalListNode allows to typeset a vertical list of lines</li>
     <li>NEW: added \c \\substack[lcr]{...\\\\...} , \c \\lsubstack{...\\\\...} , \c \\rsubstack{...\\\\...} instructions</li>
+    <li>NEW: added support for flushleft/flushright/center-environments with linebreaks</li>
   </ul></li>
 </ul>
 

examples/jkqtmathtext_test/testform.cpp

@@ -72,6 +72,9 @@ TestForm::TestForm(QWidget *parent) :
     const auto mathDecoExample=[](const QString& deco)->QString { return "\\"+deco+"{x}\\"+deco+"{i}\\"+deco+"{X}\\"+deco+"{\\psi}\\"+deco+"{abc}"; };
     ui->cmbTestset->addItem("decoration: math", "$"+mathDecoExample("vec")+" -- "+mathDecoExample("grave")+" -- "+mathDecoExample("acute")+" -- "+mathDecoExample("dot")+" -- "+mathDecoExample("ddot")+" -- "+mathDecoExample("ocirc")+" -- "+mathDecoExample("overline")+" -- "+mathDecoExample("underline")+" -- "+mathDecoExample("hat")+" -- "+mathDecoExample("widehat")+" -- "+mathDecoExample("check")+" -- "+mathDecoExample("widecheck")+" -- "+mathDecoExample("breve")+" -- "+mathDecoExample("tilde")+" -- "+mathDecoExample("widetilde")+" -- "+mathDecoExample("uul")+" -- "+mathDecoExample("ool")+" -- "+mathDecoExample("bar")+" -- "+mathDecoExample("arrow")+" -- "+mathDecoExample("cancel")+" -- "+mathDecoExample("bcancel")+" -- "+mathDecoExample("xcancel")+" -- "+mathDecoExample("sout")+"$");
     ui->cmbTestset->addItem("decoration: text", "Text \\ul{underlined Text Equator} -- \\ol{overlined Text Equator} -- \\sout{striked out Text Equator} -- \\cancel{canceled out Text Equator} -- \\bcancel{b-canceled out Text Equator} -- \\xcancel{x-canceled out Text Equator}");
+    ui->cmbTestset->addItem("text: flushleft", "\\begin{flushleft}text\\\\\\textbf{2^{nd} line of text}\\\\last \\textit{line!} $\\frac{1}{2}$\\end{flushleft}");
+    ui->cmbTestset->addItem("text: flushright", "\\begin{flushright}text\\\\\\textbf{2^{nd} line of text}\\\\last \\textit{line!} $\\frac{1}{2}$\\end{flushright}");
+    ui->cmbTestset->addItem("text: center", "\\begin{center}text\\\\\\textbf{2^{nd} line of text}\\\\last \\textit{line!} $\\frac{1}{2}$\\end{center}");
     ui->cmbTestset->addItem("mathtest", "This is normal text: $this is math:\\langle r^2(\\tau)\\rangle=\\left\\langle (\\vec{r}(t)-\\vec{r}(t+\\tau) )^2\\right\\rangle\\ \\ \\ g(\\tau)=\\frac{1}{N}\\cdot\\left(1+\\frac{2}{3}\\frac{\\langle r^2(\\tau)\\rangle}{w_{xy}^2}\\right)^{-1}  \\lfloor\\rfloor\\lceil\\rceil\\langle\\rangle\\left\\{\\vec{a}\\left|\\|\\vec{a}\\|_2\\geq2\\right.\\right\\} \\vec{r}\\vec{R}\\frac{\\sqrt{\\sqrt{\\sqrt{\\sum_{i=0}^\\infty \\hat{i}^2}+y^\\alpha}+1}}{\\dot{v}\\equiv\\ddot{r}}\\argmin_{\\vec{k}}\\sum_{\\sqrt{i}=0}^{N}\\int_{x_0}^{x_1}\\left(\\left(\\left(x\\right)\\right)\\right)\\underbrace{\\left[\\left\\{\\frac{\\partial f}{\\partial x}\\right\\}\\cdot\\frac{1}{2}\\right]}{\\text{underbraced text \\hbar}}\\cdots\\frac{\\sqrt{\\sum_{i=0}^2 \\hat{i}^2}+y^\\alpha}{\\dot{v}\\equiv\\ddot{r}}, \\hat{t}\\hat{T} \\overbrace{\\left|\\sqrt{x\\cdot Y}\\right|}{\\propto\\bbN\\circ\\bbZ}   \\left<\\arrow{x(\\tau)}\\cdot\\vec{R}(t+\\bar{\\tau})\\right>   \\alpha\\beta\\gamma\\delta\\epsilon\\Gamma\\Delta\\Theta\\Omega  \\left\\_\\left~\\cbrt{\\hbar\\omega}\\right~\\right\\_$");
     ui->cmbTestset->addItem("math: upper/lower parantheses test:", "$\\text{bblabla} \\frac{1}{2}\\cdot\\left(\\frac{1}{\\mathrm{e}^x+\\mathrm{e}^{-x}}\\right)\\cdot\\left(\\frac{1}{\\frac{1+2}{5+x}}\\right)\\cdot\\left(\\frac{1}{\\exp\\left[-\\frac{y^2}{\\sqrt{x}}\\right]\\cdot\\exp\\left[-\\frac{1}{\\frac{1}{2}}\\right]}\\right) $");
     ui->cmbTestset->addItem("math: ACF test", "$g_{rg}^{ab}(\\tau)=\\frac{1}{N}\\cdot\\left(1+\\frac{2}{3}\\frac{\\langle r^2(\\tau)\\rangle}{w_{xy}^2}\\right)^{-1}\\cdot\\left(1+\\frac{2}{3}\\frac{\\langle r^2(\\tau)\\rangle}{w_{xy}^2}\\right)^{-\\frac{1}{2}}$");

lib/jkqtmathtext/jkqtmathtext.cpp

@@ -1491,8 +1491,9 @@ JKQTMathTextNode* JKQTMathText::parseLatexString(bool get, JKQTMathTextBraceType
                 if (nl->hasChildren()) nl->getLastChild()->setSubSuperscriptAboveBelowNode(false);
             } else if (currentInstructionName=="begin") {
                 if (getToken()==MTTopenbrace && getToken()==MTTtext) {
-                    QString envname=currentTokenName;
+                    const QString envname=currentTokenName;
-                    while (currentToken!=MTTclosebrace) getToken(); // find closing brace '}' after '\\begin{name'
+                    getToken();
+                    if (currentToken!=MTTclosebrace) error_list.append(tr("error @ ch. %1: didn't find '}' after environment start '\\begin{%2'").arg(currentTokenID).arg(envname)); // find closing brace '}' after '\\begin{name'
                     if (envname=="matrix" || envname=="array" || envname=="aligned" || envname=="align" || envname=="cases" || envname=="pmatrix"|| envname=="bmatrix"|| envname=="Bmatrix"|| envname=="vmatrix"|| envname=="Vmatrix") {
                         QVector< QVector<JKQTMathTextNode*> > items;
                         //int lines=0;
@@ -1522,6 +1523,17 @@ JKQTMathTextNode* JKQTMathText::parseLatexString(bool get, JKQTMathTextBraceType
                         else if (envname=="Vmatrix") nl->addChild(new JKQTMathTextBraceNode(this, MTBTDoubleLine, MTBTDoubleLine, new JKQTMathTextMatrixNode(this, items)));
                         else nl->addChild(new JKQTMathTextMatrixNode(this, items));
                         //std::cout<<"  creating matrix-node ... done!\n";
+                    } else if (envname=="center" || envname=="document" || envname=="flushleft" || envname=="flushright") {
+                        JKQTMathTextHorizontalAlignment alignment=MTHALeft;
+                        if (envname=="document") alignment=MTHALeft;
+                        else alignment=String2JKQTMathTextHorizontalAlignment(envname);
+                        JKQTMathTextVerticalListNode* vlist = new JKQTMathTextVerticalListNode(this, alignment, 1.0, JKQTMathTextVerticalListNode::SMDefault, MTVOFirstLine );
+                        nl->addChild(vlist);
+                        bool first=true;
+                        while (first || currentToken==MTTinstructionNewline) {
+                            vlist->addChild(parseLatexString(true, MTBTAny, envname));
+                            first=false;
+                        }
                     } else {
                         error_list.append(tr("error @ ch. %1: unknown environment '%2'").arg(currentTokenID).arg(envname));
                     }

lib/jkqtmathtext/jkqtmathtext.h

@@ -202,6 +202,14 @@ class JKQTMathTextNode; // forward
       - <code>$\\rsubstack{...\\\\...}$</code> \image html jkqtmathtext/jkqtmathtext_rsubstack.png
     .
 
+    \subsection JKQTMathTextSuppoertedLaTeXTextAlignment Environments with Multi-line text
+    Several environments are supported that allow to layout text with linebreaks and different alignemnts:
+      - <code>$\\begin{document} ... \\\\ ... \\end{document}$</code> \image html jkqtmathtext/jkqtmathtext_beginflushleft.png
+      - <code>$\\begin{flushleft} ... \\\\ ... \\end{flushleft}$</code> \image html jkqtmathtext/jkqtmathtext_beginflushleft.png
+      - <code>$\\begin{flushright} ... \\\\ ... \\end{flushright}$</code> \image html jkqtmathtext/jkqtmathtext_beginflushright.png
+      - <code>$\\begin{center} ... \\\\ ... \\end{center}$</code> \image html jkqtmathtext/jkqtmathtext_begincenter.png
+    .
+
     \section JKQTMathTextSuppoertedFonts Font Handling
     
     Several fonts are defined as properties to the class:

lib/jkqtmathtext/jkqtmathtexttools.cpp

@@ -781,8 +781,8 @@ QString JKQTMathTextHorizontalAlignment2String(JKQTMathTextHorizontalAlignment t
 JKQTMathTextHorizontalAlignment String2JKQTMathTextHorizontalAlignment(QString tokenName)
 {
     tokenName=tokenName.toLower().trimmed();
-    if (tokenName=="l" || tokenName=="left") return MTHALeft;
+    if (tokenName=="l" || tokenName=="left" || tokenName=="flushleft") return MTHALeft;
-    if (tokenName=="r" || tokenName=="right") return MTHARight;
+    if (tokenName=="r" || tokenName=="right" || tokenName=="flushright") return MTHARight;
     if (tokenName=="c" || tokenName=="center" || tokenName=="centered") return MTHACentered;
     return MTHACentered;
 }